Declaration of war by the United Kingdom

A declaration of war is a formal declaration issued by a national government indicating that a state of war exists between that nation and another. In the United Kingdom, only the Monarch has the power to declare War and peace, under the Royal Prerogative. There has been a debate regarding whether the Prime Minister should have this power. This was attempted in 1999 with the introduction of the Military Action Against Iraq (Parliamentary Approval) Bill however Queen Elizabeth II refused to grant her consent to allow it to be heard in Parliament so it was dropped.

Formal declarations of war by the United Kingdom

The following table refers to declarations of war since the original Act of Union in 1707.

This list is incomplete; you can help by expanding it.

War or conflict	Opponent(s)	Initial authorisation	Declaration	Monarch	Prime Minister	Conclusion
War of the Quadruple Alliance	Spain	17 December 1718		George I	None	Treaty of The Hague, 17 February 1720.
War of Jenkins' Ear	Spain	23 October 1739		George II	Robert Walpole	Treaty of Aix-la-Chapelle, 18 October 1748.
War of the Austrian Succession	France	31 March 1744			Henry Pelham
Seven Years' War	France	17 May 1756	Declaration on France		Thomas Pelham-Holles	Treaty of Paris, 10 February 1763. British victory. Birth of the British Empire.
	Spain	4 January 1762	Declaration on Spain	George III
American Revolutionary War	France	17 March 1778	Declaration on France		Lord North	Treaty of Versailles, 3 September 1783.
	Spain	1779	Declaration on Spain			Treaty of Versailles, 3 September 1783.
Fourth Anglo-Dutch War	The Netherlands	December 1780	Declaration on the Dutch Republic			Treaty of Paris, 20 May 1784.
Napoleonic Wars	France	18 May 1803			Henry Addington
Crimean War	Russia	28 February 1854	Declaration on the Russian Empire	Victoria	Earl of Aberdeen	Treaty of Paris, 30 March 1856
Anglo-Zulu War	Zulu tribe	11 January 1879	Ultimatum by Sir Henry Bartle Frere		Benjamin Disraeli	The war ended the Zulu nation's independence.
First World War	Germany	4 August 1914	Declaration on Germany	George V	H. H. Asquith	Armistice with Germany, 11 November 1918. Treaty of Versailles, 28 June 1919.
	Austria-Hungary	12 August 1914	Declaration on Austria-Hungary			Austria: Treaty of Saint-Germain-en-Laye, 10 September 1919. Hungary: Treaty of Trianon, 4 June 1920.
	Ottoman Empire	5 November 1914	Declaration on the Ottoman Empire			Treaty of Sèvres, 10 August 1920.
	Bulgaria	15 October 1915	Declaration on Bulgaria			Treaty of Neuilly-sur-Seine, 27 November 1919.
Second World War	Germany	3 September 1939	Declaration on Germany	George VI	Neville Chamberlain	Treaty on the Final Settlement with Respect to Germany, 12 September 1990. The Potsdam Agreement on 2 August 1945 agreed the subdivision of Germany following the surrender on 8 May 1945. Austria was part of Germany when War was declared, and was formally re-established at the Treaty of Vienna on 15 May 1955.
	Italy	11 June 1940	Declaration on Italy		Winston Churchill	Armistice with Italy, 3 September 1943. The final peace treaty between Italy and the Allies was signed in Paris on 10 February 1947.
	Finland	6 December 1941	Declaration on Finland			Moscow Armistice, 19 September 1944. The final peace treaty between Finland and the Allies was signed in Paris on 10 February 1947.
	Hungary	6 December 1941	Declaration on Hungary			The final peace treaty between Hungary and the Allies was signed in Paris on 10 February 1947.
	Romania	6 December 1941	Declaration on Romania			Armistice with Romania, 12 September 1944. The final peace treaty between Romania and the Allies was signed in Paris on 10 February 1947.
	Japan	8 December 1941	Declaration on Japan			Treaty of San Francisco, 8 September 1951. This followed the Surrender of Japan on 15 August 1945 and the Occupation of Japan which began on 28 August 1945.
	Bulgaria	13 December 1941	Declaration on Bulgaria			Armistice with Bulgaria, 28 October 1944. The final peace treaty between Bulgaria and the Allies was signed in Paris on 10 February 1947.
	Thailand	25 January 1942	Declaration on Thailand

Military engagements of the United Kingdom (not formally declared)

This list is incomplete; you can help by expanding it.

War or conflict	Opponent(s)	Initial authorisation	Declaration	Monarch	Prime Minister	Conclusion
Malayan Emergency	Malayan Communist Party *Malayan Races Liberation Army	16 June 1948	Undeclared guerrilla war against Malaysian Communist Forces	George VI & Elizabeth II	Sir Winston Churchill (1948-1955) Sir Anthony Eden (1955-1957) Harold Macmillan (1957-1960)	Malayan independence 31 August 1957 under non-communist government; 31 July 1960 independent Malayan Government declares state of emergency over; Communist leader Chin Peng exiled from Malaya
Korean War	Democratic People's Republic of Korea People's Republic of China	25 June 1950	No declaration of war; authorised by UNSC Resolution 84		Sir Winston Churchill	Ongoing (no formal peace treaty signed); Armistice signed 27 July 1953; Division of Korea
Mau Mau Uprising	'Mau Mau'	20 October 1952	State of Emergency declared by British Governor in colonial Kenya	Elizabeth II	Sir Winston Churchill (1952-1955) Sir Anthony Eden (1955-1956)	Rebel leader Dedan Kimathi captured on 21 October 1956; Kenyan independence on 12 December 1963
Iranian coup d'etat	Imperial State of Iran (elected Government)	15 August 1953	No declaration of war; coup d'etat orchestrated by the intelligence agencies of the United Kingdom and the United States		Sir Winston Churchill	Overthrow of elected Government; Restoration of absolute monarchy in Iran until 1979 revolution
Suez Crisis	Egypt	31 October 1956	No declaration of war on Egypt		Sir Anthony Eden	Egyptian political victory; Coalition military victory, with subsequent forced Anglo-French withdrawal; Israeli occupation of Sinai (until 1957); United Nations cease-fire; UNEF deployment in Sinai; Straits of Tiran re-opened to Israeli shipping; Collapse of the British Eden government;
Aden Emergency	National Liberation Front (NLF) Front for the Liberation of Occupied South Yemen (FLOSY)	10 December 1963	State of Emergency declared in British Crown Colony of Aden and Aden Protectorate		Sir Alec Douglas-Home (1963-1964) Harold Wilson (1963-1967)	30 November 1967 British forces withdraw from Aden; No agreement on succeeding government; NLF seize power and establish People's Republic of South Yemen
Falklands War	Argentina	2 April 1982	No declaration of war on Argentina		Margaret Thatcher	No peace treaty signed; Status quo ante bellum
Gulf War	Iraq under Saddam Hussein	17 January 1991	No declaration of war on Iraq; authorised by UNSC Resolution 678		John Major	Ceasefire 28 February 1991; Iraq forced to withdraw from Kuwait and accept UN resolutions
Bosnian War (NATO intervention in Bosnia)	Republika Srpska	16th July 1992	No declaration of war on Republika Srpska; authorised by UNSC Resolution 816			Dayton Accords
Bombing of Iraq (December 1998)	Iraq under Saddam Hussein	16 December 1998	No declaration of war on Iraq		Tony Blair	Ceasefire
Kosovo War (NATO bombing of Yugoslavia)	FR Yugoslavia	24 March 1999	No declaration of war on Yugoslavia			Kumanovo Treaty
British intervention in Sierra Leone (Operation Palliser)	Revolutionary United Front	7 May 2000	No declaration of war on Revolutionary United Front; Intervention in Sierra Leone Civil War			Shift in balance of power in favour of Government of Sierra Leone Rebel forces repelled from area around the capital, Freetown
War in Afghanistan	Taliban	7 October 2001	No declaration of war on Afghanistan		Tony Blair (2001-2007) Gordon Brown (2007-2010) David Cameron (2010-ongoing)	Removal of Taliban government; Ongoing
Iraq War	Iraq under Saddam Hussein	20 March 2003	No declaration of war on Iraq		Tony Blair (2003-2007) Gordon Brown (2007-2009)	No peace treaty signed; Saddam Hussein overthrown; Coalition Provisional Authority governs Iraq (21 April 2003 - 28 June 2004) 30 April 2009 - British withdrawal from Iraq
2011 Libyan civil war	Libya	17 March 2011	No declaration of war on Libya; authorised by UNSC Resolution 1973		David Cameron	October 31, 2011

See also

• Declaration of war
• List of wars involving Great Britain
• Declaration of war by Canada
• Declaration of war by the United States
• War on Terrorism

External links

• War Powers and Treaties: Limiting Executive Powers (pub. October 2007)