List of proposed state mergers

For proposed annexations of non-sovereign territories, see List of irredentist claims or disputes.

This is a list of proposed state mergers, including both current and historical proposals originating from sovereign states or organizations. The entities listed below differ from separatist movements in that they would form as a merger or union of two or more existing states, territories, colonies or other regions, becoming either a federation, confederation or other type of unified sovereign state.

Historical

Early modern period

Proposed state	Components	Time period	Successful?	Notes
Swiss Confederation	Uri Schwyz Unterwalden	1307	Yes	Three cantons formed the initial Confederation in the 1307 Rütlischwur, followed by the 1315 Pact of Brunnen; ten more cantons joined over the life of the Confederacy.
Polish–Lithuanian Commonwealth	Kingdom of Poland Grand Duchy of Lithuania	1569	Yes	Union of Lublin
Polish–Lithuanian–Muscovite Commonwealth	Polish–Lithuanian Commonwealth Tsardom of Russia	1574–1658	No
Iberian Union	Crown of Castile Crown of Aragon Crown of Portugal	1580–1640	Yes	Portugal became part of the realms of the Spanish Habsburg (Casa de Austria) following the death of Henry I of Portugal but resumed its independence 60 years later.
Polish–Lithuanian–Ruthenian Commonwealth	Polish–Lithuanian Commonwealth Cossack Hetmanate	1658–1659	No	Treaty of Hadiach
Kingdom of Great Britain	Kingdom of England Kingdom of Scotland	1707	Yes	Though having been ruled since 1603 in personal union when James VI succeeded both the English and Scottish crowns both countries remained separate sovereign nations states until 1706 when the Treaty of Union unified them into a single entity.
United States	Connecticut Delaware Georgia Maryland Massachusetts New Hampshire New Jersey New York North Carolina Pennsylvania Rhode Island South Carolina Virginia	1775–1788	Yes	Constitution of the United States is ratified by the Thirteen Colonies, replacing the Articles of Confederation and thereby forming a Federal government.
Dutch Republic	Dutch Republic United Belgian States	1789–1790	No	During the Brabant Revolution, Hendrik Van Der Noot, Prime Minister of the young Belgian state proposed incorporating the confederation into the Dutch Republic. Later Willem I admitted that his idea to unite the Low Countries under the United Kingdom of the Netherlands was influenced by Van Der Noots proposal.

19th century

Proposed state	Components	Time period	Successful?	Notes
United Kingdom of Great Britain and Ireland	Kingdom of Great Britain Kingdom of Ireland	1800	Yes	Acts of Union 1800. Most of Ireland left the union as the Irish Free State in 1922, while Northern Ireland remained part of the United Kingdom.
United Kingdom of the Netherlands	Sovereign Principality of the United Netherlands Provisional Government of Belgium (1814)	1815	Yes
Gran Colombia	United Provinces of New Granada Second Republic of Venezuela Real Audiencia of Quito	1819–1830	Yes
First Mexican Empire	First Mexican Empire Captaincy General of Guatemala	1822–1823	Yes	Central America was annexed into the First Mexican Empire. After the dissolution of the Empire only Chiapas choose to remain part of Mexico, the rest became the Federal Republic of Central America. Costa Rica in particular was split between inner factions in favor and against the annexation ending in a Civil War. The pro-Mexican provinces declared membership but were not recognized by the pro-independence provinces.
Federal Republic of Central America	El Salvador Honduras Nicaragua Guatemala Los Altos Costa Rica	1823–1841	Yes
Costa Rica	Costa Rica Nicoya	1824	Yes	Annexation of Nicoya
Federation of the Andes	Colombia Peru Bolivia	1826	No	Proposed merger of the countries liberated by Simón Bolivar into a single state.
Peru–Bolivian Confederation	Peru Bolivia	1829–1836	Yes
Italian United Provinces	Duchy of Parma Duchy of Modena and Reggio Grand Duchy of Tuscany Romagna	1831	Yes
Rio Uruguay	Riograndense Republic Uruguay	1836	No	Riograndense forces were financially and indirect military supported by the Uruguayan government led by José Fructuoso Rivera. The Uruguayans had the intention of creating a political union with the Riograndense Republic to create a new stronger state.
United States	United States Upper Canada	1837-1838	No	Rebellions of 1837–1838. Republicans in Upper Canada pursued annexation by the United States.
United States	United States Second Federal Republic of Mexico	1846-1848	No	During the Mexican–American War there were some calls and debates regarding American annexation of Mexico in its entirety.
United Kingdom of Ecuador, Peru and Bolivia	Ecuador Peru Bolivia	1846	No	Plan by Juan José Flores to re-conquer the former Bourbon Crown territories of the Viceroyalty of Peru.
Federation of Central America	El Salvador Honduras Nicaragua	1852	Yes	Second attempt at unification that lasted for less than a month.
Liberia	Republic of Liberia Republic of Maryland	1854–1857	Yes	Republic of Maryland was officially named Maryland in Liberia during its independence referendum on 29 May 1854.
United Principalities of Moldavia and Wallachia	Principality of Moldavia Principality of Wallachia	1859	Yes	Becomes Kingdom of Romania in 1881.
United Provinces of Central Italy	Duchy of Parma Duchy of Modena and Reggio Grand Duchy of Tuscany Romagna	1859	Yes
Kingdom of Sardinia	Kingdom of Sardinia United Provinces of Central Italy	1860	Yes
Belgium–Netherlands Confederation	Belgium Netherlands	1860	No	Belgian Prime Minister Charles Rogier proposed a personal union of Belgium and the Netherlands due to fear of French invasion.
Kingdom of Italy	Kingdom of Sardinia Kingdom of Lombardy–Venetia Papal States Kingdom of the Two Sicilies	1860–1870	Yes	Expedition of the Thousand. Although the Kingdom of Italy was proclaimed in 1861, the Italian unification is generally considered to have been incomplete until after the annexation of the Kingdom of Lombardy–Venetia in 1866 and the capture of Rome in 1870.
Confederate States of America	State of South Carolina State of Mississippi State of Florida State of Alabama State of Georgia State of Louisiana State of Texas Commonwealth of Virginia State of Arkansas State of North Carolina State of Tennessee	1861	Yes	American Civil War
Spanish Empire	Spanish Empire First Dominican Republic	1861	Yes	In 1861 general Pedro Santana asked Queen Isabella II of Spain to retake control of the Dominican Republic after a period of only 17 years of independence. Spain accepted his proposal and made the country a colony again.
Kingdom of Greece	Kingdom of Greece United States of the Ionian Islands	1864	Yes	Treaty of London (1864)
North German Confederation	Kingdom of Prussia Kingdom of Saxony Grand Duchy of Hesse Duchy of Mecklenburg-Schwerin Grand Duchy of Mecklenburg-Strelitz Grand Duchy of Oldenburg Saxe-Weimar-Eisenach Duchy of Anhalt Duchy of Brunswick Duchy of Saxe-Altenburg Saxe-Coburg-Gotha Saxe-Meiningen Various other small principalities and free cities	1866	Yes	Following the Austro-Prussian War of 1866 and the annexation by Prussia of Austria's northern German ally states Otto von Bismarck proposed to unify Prussia and its own German ally states into a single Federation. Consequently the North German Constitution was adopted, with the provision that the southern German minor states could enter into the union when politically feasible.
Dominion of Canada	Province of Canada Province of New Brunswick Province of Nova Scotia	1867	Yes	Canadian Confederation
United States	United States Greenland	1867–2019	No	The idea for the United States to buy Greenland was first proposed during the administration of President Andrew Johnson, when, in 1867, Secretary of State William H. Seward unsuccessfully proposed buying Greenland and Iceland from the Danish Kingdom. A post-World War II bid was also declined by Denmark. In 2018 and 2019, President Donald Trump spoke to aides about acquiring the island; Greenlandic and Danish officials firmly rebuffed the suggestion that the island could be sold.
Antillean Confederation	Captaincy General of Cuba Captaincy General of Puerto Rico Second Dominican Republic	1869–1870	No	Proposed by Ramón Emeterio Betances.
German Empire	Lesser Germany: North German Confederation Kingdom of Bavaria Kingdom of Württemberg Grand Duchy of Baden Grand Duchy of Hesse Alsace-Lorraine Greater Germany also comprended: Austrian Empire	1871	Yes	The German question regarding the competing ideas of "Greater Germany" and "Lesser Germany" (whether or not a united Germany should include the Austrian Empire) was settled with the Austro-Prussian War in 1866, in which Prussia assumed leadership of the various minor German nation states. The Unification of Germany (excluding Austria) was completed after German victory over the French in the Franco-Prussian War.
Bulgaria–Romania	Bulgaria Romania	1878–1879	No	Proposed personal union, German prince Alexander of Battenberg is elected instead.
United States of Peru–Bolivia	Peru Bolivia	1880	No	Proposed state by Nicolás de Piérola and Narciso Campero, also called the Federal Repulic of the Incas.
Kingdom of Spain	Kingdom of Spain Captaincy General of the Philippines	1880–1898	No	By the Propaganda Movement led by Filipinos educated in Europe which advocated the Philippine islands be converted from a colony to a province of Spain.
Principality of Bulgaria	Bulgaria Autonomous Province of East Rumelia	1885–1886	Yes	After Bulgaria defeated Serbia in the Serbo-Bulgarian War of 1885, Bulgaria nearly doubled in size when East Rumelia was incorporated within its borders. Bulgaria officially annexed it from the Ottoman Empire in 1885.
Bulgaria–Romania	Bulgaria Romania	1886–1887	No	Proposed personal union, rejected by Carol I of Romania due to Russian pressure.
Dominion of Canada	Dominion of Canada Jamaica	1890	No	In the late 19th century, there was some discussion of some form of political union between Canada and Jamaica.
Greater Republic of Central America	El Salvador Honduras Nicaragua Considered joining: Costa Rica Guatemala	1895–1898	Yes
Angloworld	United Kingdom United States Canada Colony of New South Wales Colony of Queensland Colony of Western Australia Colony of South Australia Colony of Tasmania Colony of Victoria Colony of New Zealand Cape Colony Colony of Natal Orange River Colony Transvaal Colony	1860–1914	No	Numerous prominent transatlantic thinkers proposed a union of the United States and the United Kingdom, as well as a consolidation of the United Kingdom and its remaining white settler colonies (Canada, South Africa, Australia, New Zealand).

20th century

Proposed state	Components	Time period	Successful?	Notes
Commonwealth of Australia	New South Wales Queensland South Australia Tasmania Victoria Western Australia Also invited: Colony of Fiji Colony of New Zealand	1901	Yes	Federation of Australia. New Zealand had many disagreements with the Austrialian government and decided to be out of the federation.
Franco-British Union	France United Kingdom	1904–1956	No	A Franco-British Union is a concept for a union between the two independent sovereign states of the United Kingdom and France. Such a union was proposed during certain crises of the 20th century; it has some historical precedents. In April 1904 France and the United Kingdom signed a series of agreements, known as the Entente Cordiale, which marked the end of centuries of intermittent conflict between the two powers, and the start of a period of peaceful co-existence. Nationalist political leaders from both sides were uncomfortable with the idea of such a merging.
Union of South Africa	Cape Colony Colony of Natal Orange River Colony Transvaal Colony	1909	Yes	Union of South Africa
Balkan Socialist Federation	Kingdom of Yugoslavia Principality of Albania Kingdom of Bulgaria	1910–1916	No
Dominion of Canada	Dominion of Canada The Bahamas	1911	No	In 1911, at the request of the Bahamian House of Assembly, the Canadian and the Bahamian governments began serious negotiations for Bahamian accession to the Canadian confederation. However, a racial panic ignited by the migration of over one thousand African-Americans fleeing violence in Oklahoma derailed the discussions. Prime Minister Wilfrid Laurier turned against the idea, citing incompatible "ethnical origin". After Laurier lost the September 1911 federal election, Bahamian Governor William Grey-Wilson travelled to Canada to reopen accession talks with newly elected PM Robert Borden. In a meeting between Grey and Borden on 18 October 1911, Borden rejected the possibility of taking the Bahamas into the Canadian confederation. His reasoning was that the events of the past year had proved that Canadian public opinion would not countenance the admission of a majority-black province. The British Colonial Office concurred: "No doubt for the moment the Dominion government would safeguard their interests, but there are signs of the rise of a colour question in Canada and in any case it cannot be long before U.S. opinion gives the tone to Canada in regard the Negro."
Kingdom of Greece	Cretan State Kingdom of Greece	1913	Yes	Crete rebelled against Ottoman rule during the Cretan Revolt of 1866-69 and used the motto "Crete, Enosis, Freedom or Death". The Cretan State was established after the intervention of the Great Powers, and Cretan union with Greece occurred de facto in 1908 and de jure in 1913 by the Treaty of Bucharest.
Hungary–Romania	Kingdom of Romania Republic and Kingdom of Hungary	1917–1920	No	Federation or personal union between the Kingdom of Romania and the Kingdom/Republic of Hungary under one monarch. Proposals were mostly enhanced in 1919 and 1920, but they continued to exist up to the Second World War.
Kingdom of Yugoslavia	Kingdom of Serbia Kingdom of Montenegro State of Slovenes, Croats and Serbs	1918	Yes	Creation of Yugoslavia
Kingdom of Romania	Kingdom of Romania Moldavian Democratic Republic Bukovina Transylvania	1918	Yes	Great Union, Union of Bessarabia with Romania, Union of Bukovina with Romania, Union of Transylvania with Romania
Intermarium	Belarusian People's Republic Czechoslovak Republic Estonia Finland Hungarian People's Republic Latvia Lithuania Polish Republic Kingdom of Romania Ukrainian People's Republic Kingdom of Yugoslavia Kingdom of Bulgaria	November or December 1918	No	Also called "Międzymorze" in Polish. Suggested shortly after World War I to combat the influences of Germany and Russia.
Transcaucasian Democratic Federative Republic	Democratic Republic of Georgia Democratic Republic of Armenia Azerbaijan Democratic Republic	1918	Yes	A short-lived South Caucasian state that extended across what are now the modern-day countries of Georgia, Armenia and Azerbaijan plus parts of Eastern Turkey as well as Russian border areas. The state only lasted for a month before Georgia declared independence, followed shortly by Azerbaijan and Armenia.
Weimar Republic	Weimar Republic Republic of German-Austria	1918–1919	No	Following the disintegration of Austria-Hungary in the final days of World War I the German-speaking territories of the former Austria-Hungary attempted to begin a process of integration into Weimar Germany. The Allies did not favor the idea, and forced the Austrian rump state to sign the Treaty of Saint Germain, which prohibited Austria from uniting with Germany.
Ukrainian People's Republic	Ukrainian People's Republic West Ukrainian People's Republic	1919	Yes	Act Zluky
Patria Grande	Argentina Bolivia Chile Colombia Costa Rica Cuba Dominican Republic El Salvador Ecuador Guatemala Honduras Mexico Nicaragua Panama Paraguay Peru Puerto Rico Uruguay Venezuela	1922	No	The concept of a shared homeland or community encompassing all of Spanish America, and sometimes all of Latin America and the Caribbean. The term is associated with political ideas of Ibero-American integration, rejecting the balkanization of the Spanish Empire in the Americas that followed the Spanish American wars of independence. The term may be also used to talk specifically about projects of Hispanic American unity held by Simón Bolívar and José de San Martín.
Union of Soviet Socialist Republics	Byelorussian SSR Russian SFSR Transcaucasian SFSR Ukrainian SSR	1922	Yes	Treaty on the Creation of the Union of Soviet Socialist Republics
Union of South Africa	Union of South Africa Colony of Southern Rhodesia	1922	No	The 1922 Southern Rhodesian government referendum was held in the colony on 27 October 1922. Voters, almost all of them White, were given the options of establishing responsible government or joining the Union of South Africa. After 59% voted in favour of responsible government, it was officially granted on 1 October 1923.
Baltoscandia	Denmark Sweden Finland Norway Iceland Estonia Lithuania Latvia	1928–1960	No	The term Baltoscandia was first used by Sten de Geer in an article in "Geografiska Annaler" in 1928 and further developed by Kazys Pakštas. He envisioned Baltoscandia as an economic, political and military unit. Kazys Pakštas proposed that one of the ways for the small nations to withstand the influence coming from the large ones is to unite and to cooperate more closely among each other. As he mentions, unification is possible only among nations that are similar by their size, geographical environment, religion and culture.
Greater Indonesia	Dutch East Indies British Malaya Crown Colony of Sarawak Crown colony of North Borneo Protectorate of Brunei Crown colony of Singapore Portuguese Timor	1928	No	A political concept that sought to bring the so-called Malay race together by uniting the territories of Dutch East Indies (and Portuguese Timor) with the British Malaya and British Borneo. It was espoused by students and graduates of Sultan Idris Training College for Malay Teachers in the late 1920s, and individuals from Sumatra and Java including Mohammad Yamin and Sukarno in the 1950s. Indonesia Raya was later adapted as the name of the Indonesian national anthem in 1924.
German Reich	German Reich Federal State of Austria	1938	Yes	Anschluss
Turkey	Turkey Hatay State	1939	Yes	On 2 September 1938 the Sanjak of Alexandretta declared itself separate from the French Mandate of Syria and Lebanon, becoming the Hatay State. On 29 June 1939, the legislature voted to merge with Turkey.
Polish–Czechoslovak confederation	Polish Republic Czechoslovak Republic	1939–1948	No	Proposed by Władysław Sikorski.
Greek–Yugoslav confederation	Strictest definition: Kingdom of Greece Kingdom of Yugoslavia Loosest definition also includes: Albanian Kingdom Kingdom of Bulgaria Kingdom of Romania	1942–1944	No	The Greek-Yugoslav confederation was a political concept during World War II, sponsored by the United Kingdom and involving the Greek government-in-exile and the Yugoslav government-in-exile. The two governments signed an agreement pushing the proposal ahead, but it never got beyond the planning stage because of opposition from within the Greek and the Yugoslav governments, real world events, and the opposition of the Soviet Union. The proposal envisioned the creation of a confederation of Greece and Yugoslavia.
Ewe Land	French Togoland British Togoland	1945–1956	No	In 1945 various members of Ewe and wider Togolese leadership began the construction of political organizations which sought to decolonize French Togoland. These developed as the Comité de l'Unité Togolaise, led by Sylvanus Olympio, and the Mouvement la Jeunesse Togolaise. Both possessed political platforms that included the reunification of the French Togoland and British Togoland.
Socialist Federal Republic of Yugoslavia	Socialist Federal Republic of Yugoslavia People's Socialist Republic of Albania People's Republic of Bulgaria	1946–1948	No	Josip Broz Tito came extremely close to persuading Albania to accept integration into Yugoslavia, but relations cooled in 1948 over fears that Yugoslavia only intended to use Albania for raw materials, subsequently resulting in the expulsion of Yugoslav diplomats. Yugoslav/Bulgarian negotiations fell through when Moscow attempted to force both countries into accepting Soviet control over the merge, which caused Yugoslavia to withdraw from negotiations and precipitated the Tito–Stalin split.
India	India Junagadh State Other states	1947–1948	Yes	Political integration of India, Annexation of Junagadh
United States of Indonesia	Bangka Banjar Biliton Central Java East Borneo East Indonesia East Java East Sumatra Great Dayak Indonesia Madura Pasundan South Sumatra Southeast Borneo Riouw West Borneo	1946–1949	Yes	Following discussions between Dutch authorities and Indonesian nationalist leaders, the Linggadjati Agreement was signed on 15 November 1946, in which the unilaterally declared Republic of Indonesia agreed to the principle of a federal Indonesia including the territory controlled by the Republic and other territory in the region which the Dutch controlled at that point. The Dutch then organised the December 1946 Denpasar Conference, which led to the establishment of the State of East Indonesia, followed by a state in West Borneo. Further states were set up in former territory of the Republic after they were conquered by the Dutch in 1947. Further Dutch military action faced increasing resistance from governments of the states they had established, and this combined with international pressure caused the Dutch–Indonesian Round Table Conference to take place in The Hague from August to November 1949. This Conference resulted in the Dutch agreeing to hand over sovereignty to a federal union of these states, which officially became the Republic of the United States of Indonesia. This federation lasted only a year, as its member states agreed to dissolve themselves into a unitary state, the last stage of which took place on 17 August 1950.
India	India Princely states	1947–1950	Yes	Instrument of Accession
Pakistan	Pakistan Princely states	1947–1950	Yes	Instrument of Accession
India	India Hyderabad	1948	Yes	Annexation of Hyderabad
Dominion of Canada	Dominion of Canada Dominion of Newfoundland	1948–1949	Yes	In two rounds of referendums in 1948, the Dominion of Newfoundland had the choice of becoming an independent state, merging with the Dominion of Canada, or remaining as a British dominion. The Newfoundland Act of 1949, an Act of the Parliament of the United Kingdom, confirmed and gave effect to the Terms of Union agreed to between the then-separate Dominions of Canada and Newfoundland on 23 March 1949.
Dominion of Canada	Dominion of Canada Bermuda	1949	No	In 1949 Henry Vassey, then Chairman of the Bermuda Trade Development Board, urged the House of Assembly of Bermuda to pursue a political union with Canada. Four Methodist church congregations in Bermuda are part of the United Church of Canada, forming Bermuda Presbytery of the United Church's Maritime Conference headquartered in Sackville, New Brunswick. The same Salvation Army Church territory serves both Canada and Bermuda with many of their pastors travelling between countries. In January 2009, Nova Scotia's Premier, Rodney MacDonald, and the Premier of Bermuda, Ewart Brown, signed a five-year agreement that would strengthen Nova Scotia's ties with Bermuda and enhance service export opportunities, tourism, transportation and health links in both jurisdictions. Bermuda's ties to Canada include the Institute of Chartered Accountants of Bermuda being overseen by Canada's Chartered Professional Accounting profession.
Greece	Greece Cyprus	1950	No	An unofficial referendum on enosis (reunification) with Greece was held in Cyprus between 15 and 22 January 1950, and the proposal was approved by 95.71% of those taking part.
Indonesia	Indonesia Netherlands New Guinea	1950–1969	Yes	Following Dutch recognition of Indonesian Independence, Indonesia continued to claim the remaining Dutch territory in the region, Netherlands New Guinea, as its rightful territory. The dispute escalated into low-level conflict in 1962 following Dutch moves in 1961 to establish a New Guinea Council. Facing diplomatic pressure from the United States, fading domestic support and continual Indonesian threats to invade the territory, the Netherlands decided to relinquish control of the disputed territory in August 1962. Following a short period of UN administration, the territory was transferred to Indonesia on 1 May 1963.
Federation of Rhodesia and Nyasaland	Protectorate of Nyasaland Protectorate of Northern Rhodesia Colony of Southern Rhodesia	1953	Yes
West Germany	West Germany Saar Protectorate	1955–1957	Yes	1955 Saar Statute referendum. Saarland became a New State of Germany and exited France's economic union.
United Kingdom	United Kingdom Crown Colony of Malta	1956	No	1956 Maltese United Kingdom integration referendum
Ghana	Gold Coast British Togoland	1956	Yes	In the 1956 British Togoland status plebiscite 58% of voters supported a union with Ghana, whereas 42% voted in favor of remaining a United Nations Trust Territory under British control until neighbouring French Togoland had decided its future.
North Borneo Federation	Crown Colony of North Borneo Crown Colony of Sarawak Protectorate of Brunei	1956–1960	No	Sarawak and North Borneo merged with the independent Federation of Malaya several years later, forming Malaysia, while Brunei later became an independent state on its own.
United States of Latin Africa	Angola Belgian Congo Ruanda-Urundi French Congo Ubangi-Shari French Chad French Cameroon French Gabon Spanish Guinea São Tomé and Príncipe	1957–1959	No	Proposed union of Romance-language-speaking Central African countries envisioned by Barthélemy Boganda. Boganda first called for it in May 1957. The idea's implementation was cut short by Boganda's death in a plane crash on 29 March 1959. Boganda viewed this entity to be a counterweight to the powerful British-influenced southern bloc of South Africa and the Federation of Rhodesia and Nyasaland.
Cameroon	Cameroon Spanish Guinea	1958–1963	No	The Equatoguinean independence leader Enrique Nvo and the first formal Equatoguinean political party, IPGE, advocated for independence from Spain and a political union between Cameroon and Equatorial Guinea. The idea of a union was deemed unfeasible after the 1963 Spanish Guinean autonomy referendum.
West Indies Federation	British Barbados British Jamaica British Leeward Islands (except the Virgin Islands) British Trinidad and Tobago British Windward Islands Also invited: Crown Colony of the Bahama Islands British Guiana British Honduras British Virgin Islands	1958	Yes	The expressed intention of the Federation was to create a political unit that would become independent from Britain as a single state. However, before that could happen, the Federation collapsed due to internal political conflicts.
United Arab Republic	Republic of Egypt Syrian Republic	1958	Yes	A short-lived Pan-Arab state.
United Arab States	United Arab Republic Mutawakkilite Kingdom of Yemen	1958	Yes	Loose confederation between the United Arab Republic and North Yemen.
Arab Federation	Kingdom of Iraq Hashemite Kingdom of Jordan	1958	Yes	An attempt to unify the two Hashemite kingdoms of Iraq and Jordan. While successful, the short-lived union was disestablished after a military coup deposed Faisal II of Iraq.
Somali Republic	Trust Territory of Somalia State of Somaliland	1960	Yes	On 26 June 1960 the former British Somaliland protectorate briefly obtained independence as the State of Somaliland, with the Trust Territory of Somaliland following suit five days later. The following day, on 27 June 1960, the newly convened Somaliland Legislative Assembly approved a bill that would formally allow for the union of the State of Somaliland with the Trust Territory of Somaliland on 1 July 1960. Following the collapse of Barre's government in early 1991 local authorities, led by the SNM, unilaterally declared independence from Somalia on 18 May of the same year and reinstated the borders of the former short-lived independent State of Somaliland.
East African Federation	Kenya Colony Tanganyika Territory Uganda Protectorate Sultanate of Zanzibar	1960–1964	No	Proposed political union between the four territories (one colony, two protectorates and one League of Nations mandated territory) under British rule in East Africa in the 1960s. Tanganyika proposed to delay its imminent independence in 1960 so that the four territories might achieve independence together as one federation. In 1963 the leaders of all of the territories (some now independent) pledged to work towards a federation by 1964, but ultimately disputes over the nature of the federation and concerns about sharing power led to the collapse of effort to federate. Only Tanganyika and Zanzibar eventually united in 1964.
Cameroon	Cameroon British Cameroon	1961	Partial (Southern Cameroons)	In the 1961 British Cameroons referendum, the Christian majority in the south of British Cameroon voted to integrate with Cameroon, whereas the Muslim-majority Northern areas voted to integrate with Nigeria.
Nigeria	Nigeria British Cameroon		Partial (Northern Cameroons)
India	India Portuguese State of India	1961	Yes	Annexation of Dadra and Nagar Haveli, Annexation of Goa
India	India French Settlements in India	1962	Yes
Federation of the Emirates of the South	Fadhli Audhali Beihan Dhala Lower Yafa Upper Aulaqi Sheikhdom Alawi Aqrabi Dathina Haushabi Lahej Lower Aulaqi Maflahi Shaib Wahidi	1962	Yes	The Federation of the Emirates of the South (Arabic: اتحاد إمارات الجنوب العربي‎ Ittiḥād ʾImārāt al-Janūb al-ʿArabiyy) was an organization of states within the British Aden Protectorate in what would become South Yemen. The Federation of six states was inaugurated in the British Colony of Aden on 11 February 1959, and the Federation and Britain signed a “Treaty of Friendship and Protection,” which detailed plans for British financial and military assistance. It subsequently added nine states and, on 4 April 1962, became known as the Federation of South Arabia. This was joined by the Aden Colony on 18 January 1963.
Maphilindo	Malaya Indonesia Philippines	1963	No	Proposals to create a union of the people of the Malay race and deal with the continued decolonisation of Southeast Asia led to leaders of the three countries signing the Manila Accord on 5 August 1963. However, cooperation quickly broke down following the formation of Malaysia by Malaya and other former British colonies in the region, which was opposed by Indonesia and the Philippines.
Malaysia	Federation of Malaya Crown Colony of North Borneo Crown Colony of Sarawak Colony of Singapore Also invited: Brunei	1963	Yes	Singapore was expelled from the federation on 9 August 1965 later forming the Republic of Singapore. Brunei Sultan Omar Ali Saifuddien III accepted the idea but rejected after the Brunei revolt.
United Republic of Tanzania	Republic of Tanganyika People's Republic of Zanzibar	1964	Yes
Australia	Australia Nauru	1964–1965	No	In 1963 the Australian Government proposed that the citizens of Nauru, a United Nations trust territory under Australian administration, would move to Curtis Island and become Australian citizens. By that time, Nauru had been extensively mined for phosphate by companies from Australia, Britain and New Zealand damaging the landscape so much that it was thought the island would be uninhabitable by the 1990s. The cost of resettling the Nauruans on Curtis Island was estimated to be £10 million, which included housing and infrastructure and the establishment of pastoral, agricultural, and fishing industries. However, the Nauruan people did not wish to become Australian citizens and wanted to be given sovereignty over Curtis Island to establish themselves as an independent nation, which Australia would not agree to. Nauru rejected the proposal to move to Curtis Island, instead choosing to become an independent nation operating their mines in Nauru. Nauru became self-governing in January 1966, and following a two-year constitutional convention, it became independent in 1968 under founding president Hammer DeRoburt.
Territory of the Marianas	Territory of Guam Commonwealth of the Northern Mariana Islands	1969	No	1958 Saipan integration referendum, 1961 Northern Mariana Islands status referendum, 1963 Northern Mariana Islands integration referendum, 1969 Guamanian unification with the Northern Mariana Islands referendum, 1969 Northern Mariana Islands status referendum
United Arab Emirates	Abu Dhabi Dubai Sharjah Ajman Umm Al Quwain Fujairah Ras Al Khaimah Also invited: Bahrain Qatar	1971	Yes	Six independent emirates formed the United Arab Emirates on 2 December 1971. Ras Al Khaimah later joined the federation.
Federation of Arab Republics	Libya Egypt Syria Also invited: Iraq Sudan	1972–1977	Yes	An attempt by Muammar Gaddafi to build a Pan-Arab state.
Arab Islamic Republic	Libya Tunisia	1974	No	Proposed by Muammar Gaddafi.
Indochinese Federation	North Vietnam South Vietnam Democratic Kampuchea Laos	1975	No	Despite Kampuchea's cooperation with the Vietnamese, the Khmer Rouge leadership feared that the Vietnamese communists were planning to form an Indochinese federation, which would be dominated by Vietnam. In order to pre-empt any attempt by the Vietnamese to dominate them, the Khmer Rouge leadership began, as the Lon Nol government capitulated in 1975, to purge Vietnamese-trained personnel within their own ranks. Then, in May 1975, the newly formed Democratic Kampuchea began attacking Vietnam, beginning with an attack on the Vietnamese island of Phú Quốc.
India	India Sikkim	1975	Yes	After independence in 1947, joining the new Indian Union was rejected by popular vote. Sikkim grew closer to India over time, becoming a protectorate and later a suzerainty of India. With Indian pressure and support, Sikkim voted to join India in 1975.
Guinea and Cape Verde	Guinea-Bissau Cape Verde	1975	No	The African Party for the Independence of Guinea and Cape Verde (PAIGC) advocated for the independence of the colonies of Portuguese Guinea and Portuguese Cape Verde, and governed both countries immediately after independence (1974 for Guinea-Bissau, and 1975 for Cape Verde) with the goal of unifying the two. However, following a 1980 coup in Guinea-Bissau, the Cape Verde branch of the party separated to form the African Party for the Independence of Cape Verde (PAICV), ending plans for a union.
Indonesia	Indonesia East Timor	1975–1976	Yes	Indonesian invasion of East Timor
Vietnam	North Vietnam South Vietnam	1976	Yes	Fall of Saigon, Reunification Day
Solomon Islands	Solomon Islands Republic of the North Solomons	1976	No	The Interim Provincial Government announced that they would declare independence on 1 September, ahead of Papua New Guinea's own planned independence day of 16 September. On 1 September, they issued the 'Unilateral Declaration of Independence of the Republic of North Solomons'. They sought international recognition through the United Nations, but were unsuccessful. They also failed in an attempt to unite with the Solomon Islands.
Socialist Union of the Horn of Africa	Ethiopia Somalia South Yemen	1977	No	In early 1977, Castro brought together the leaders of Somalia, Ethiopia and South Yemen to create a socialist federal state in the region. General Mohamed Nur Galal was the former deputy defense minister of Somalia and the vocal point of Somalia's military contacts with Cuba at that time. He was present at the meeting in Aden in March 1977.
German Democratic Republic	German Democratic Republic (East Germany) Federal Republic of Germany (West Germany)	1979	No	Seven Days to the River Rhine
Senegambia Confederation	Senegal The Gambia	1982–1989	Yes	A loose confederation was formed, but ended due to the Gambia's lack of interest in integration.
Yemen	North Yemen South Yemen	1990	Yes	Yemeni unification
Germany	West Germany East Germany	1990	Yes	German reunification
Union of Soviet Sovereign Republics	Russian SFSR Byelorussian SSR Ukrainian SSR Azerbaijan SSR Kazakh SSR Kirghiz SSR Tajik SSR Turkmen SSR Uzbek SSR Also invited: Abkhaz ASSR South Ossetian AO Gagauz Republic Pridnestrovian SSR	1990–1991	No	1991 Soviet Union referendum
FR Yugoslavia	SR Serbia Montenegro Bosnia and Herzegovina	1991	No	Zulfikarpašić–Karadžić agreement
FR Yugoslavia	SR Serbia Montenegro	1992	Yes
Balkania	SR Serbia Montenegro Kosova	1993-2006	No	Suggested by the Kosovo Albanian politician Adem Demaçi
South Africa	South Africa Bophuthatswana Ciskei Transkei Venda	1994	Yes	During apartheid the South African Government granted nominal independence to four autonomous bantustans within it. While no external country recognized these states, South Africa strongly promoted their independence and the four mutually recognized each other. As South Africa moved to end apartheid, the African National Congress (ANC) party advocated reintegration of all bantustans, including the nominally independent ones, into a unitary South African state. Resistance to integration by leaders of some bantustans led to violence, such as in the Bisho massacre and the Bophuthatswana crisis. Nonetheless, inhabitants of all four independent bantustans participated in the 1994 South African general election, during which a new constitution came into effect which reintegrated all bantustans into South Africa.

21st century

Proposed state	Components	Time period	Successful?	Notes
United Republic of Cyprus	Cyprus Northern Cyprus	2004	No	A referendum was held in Cyprus on 24 April 2004. The two communities were asked whether they approved of the fifth revision of the United Nations proposal for reuniting the island, which had been divided since 1974. While it was approved by 65% of Turkish Cypriots, it was rejected by 76% of Greek Cypriots.
New Sudan	South Sudan Sudan	2005–2011	No	New Sudan is a concept for restructuring the Sudanese state, which was proposed by the Sudan People's Liberation Army/Movement during the Second Sudanese Civil War. The original SPLA/M Manifesto outlined 'New Sudan' as a proposed united and secular Sudanese state. The vision of 'New Sudan' was developed by Dr. John Garang, who advocated the 'New Sudan' as a democratic and pluralistic state.
Russian Federation	Russian Federation Transnistria	2006	No	Proposed Russian annexation of Transnistria
Gran Colombia	Colombia Ecuador Panama Venezuela	2008	No	Reunification of Gran Colombia, In 2008, Hugo Chávez, president of Venezuela, announced the proposal of the political restoration of the Gran Colombia, under the Bolivarian revolution.
Lucayan Federation	Bahamas Turks and Caicos Islands	2010	No	The Lucayan Archipelago (named for the original native Lucayan people), also known as the Bahama Archipelago, is an island group comprising the Commonwealth of The Bahamas and the British Overseas Territory of the Turks and Caicos Islands. The archipelago is in the western North Atlantic Ocean, north of Cuba along with the other Antilles, and east and southeast of Florida. In 2010 the leaders of The Bahamas and the Turks and Caicos Islands discussed the possibility of forming a federation.
Peru–Bolivian Confederation	Bolivia Peru	2011	No	President Ollanta Humala of Peru proposed Bolivian president Evo Morales to reunite the countries in a confederation. The Cabinets of the two countries have held joint meetings.
Russian Federation	Russia Crimea	2014	Yes	Crimea seceded from Ukraine and later conducted a referendum to join the Russian Federation and was later annexed by Russia. The referendum was extremely controversial and most countries continue to recognize Crimea as part of Ukraine.
Novorossiya	Donetsk People's Republic Luhansk People's Republic	2014	No	Novorossiya (Full name: Federal State of Novorossiya) was a proposed confederation between the two self-declared nations of the Donetsk People's Republic and the Luhansk People's Republic. The Confederation was declared on 22 May 2014. On 20 May 2015 the constituent members announced the freezing of the Novorossiya project.
Russian Federation	Russia South Ossetia	2022	No	On 30 March 2022, President Anatoly Bibilov suggested a referendum on joining Russia. The referendum would be executed on 17 July 2022 but the plan was cancelled on 30 May 2022.

Current proposals

Proposed state	Component states	First proposed	Notes
Canada	Canada Turks and Caicos Islands	1917	The proposed Canadian annexation of the Turks and Caicos Islands has been an ongoing political discussion between the two nations since Canadian Prime Minister Robert Borden first supported the idea in 1917.
China	People's Republic of China Republic of China	1949	Unification of the territories of the People's Republic of China and the Republic of China is the nominal goal of both governments, which both operate under the One-China policy. However, within the free area of the Republic of China, there is a sizeable movement to formally declare a Taiwanese state, led by the Democratic Progressive Party, which is currently in government.
India	Bangladesh India Pakistan	1953	Since the Partition of India there have been multiple calls to reunite the territories by the remerger of successor states.
Korea	Democratic People's Republic of Korea Republic of Korea	1953	Korean reunification has been a goal for both Koreas since the 1953 armistice agreement. However, proposed strategies vary between the two Koreas, with both proposing unification under one sociopolitical system while abandoning the other, similar to German reunification.
Saint Martin	Saint Martin Sint Maarten	1990	Proposed unification of the island.
Romania	Moldova Romania	1991	Due to the revolutions of the Russian Empire, Bessarabia Governorate declared secession in 1917 as the Moldavian Democratic Republic and united unconditionally with the Kingdom of Romania in 1918, before the Soviet occupation in 1940. After Moldova gained independence following the dissolution of the Soviet Union, unification of Moldova and Romania has been proposed which is supported by the Moldovan minorities according to polls and the Romanian Government.
Union State of Russia and Belarus	Belarus Russian Federation	1999	Russia and Belarus signed an agreement to form the Union State in 1999 aiming to continue deeper integration, possibly until unification.
East African Federation	Burundi DR Congo Kenya Rwanda South Sudan Tanzania Uganda	2004	Proposed political union between the seven member states of the East African Community. Federation was proposed in 2004, but in 2016 it was decided that confederation would be the short-term goal. South Sudan and the DR Congo are not as integrated as the other five members, as South Sudan only gained independence from the Sudan in 2011, and the DR Congo only joined the Community in 2022.
Albania	Albania Kosovo	2008	Since Kosovo's Independence from Serbia, talks have been made for Albania and Kosovo to unite into a Greater Albania due to Kosovo's majority ethnic Albanian population.
Central America	Costa Rica El Salvador Guatemala Honduras Nicaragua Also invited: Belize Panama	2018	Despite several historical efforts to reunite the countries that belonged to the United Provinces of Central America and later Federal Republic of Central America into one single state, the first major political figure to suggest it was the President of El Salvador Nayib Bukele.
United Turkic States	Azerbaijan Kazakhstan Kyrgyzstan Turkey Uzbekistan Also invited: Turkmenistan	2021	General Secretary Baghdad Amreyev announced that the Turkic Council aims for a united state overseeing the Turkic world.
Russian Federation	Donetsk People's Republic Luhansk People's Republic Russia Russian-occupied Kherson	2022	Leader of the DPR Denis Pushilin said that they might consider joining Russia once it controls all of Ukraine's Donetsk region. Leader of the LPR Leonid Pasechnik said that a referendum on joining Russia could be held near future. The Russian-occupied region of Kherson in Ukraine plans to ask President Vladimir Putin to incorporate it into Russia by the end of 2022

See also

• Arab Union
• Atlantic Union
• Dynastic union
• Independence referendum
• Irredentism
• List of irredentist claims or disputes
• Lists of active separatist movements
• North American Union
• Pan-Latinism
• Pan-nationalism
• Political union
• Supranational union
• Turanism
• United States of Africa
• United States of Europe