Wikipedia:Selected anniversaries/April 22
This is a list of selected April 22 anniversaries that appears on the "On this day" section of the Main Page. To suggest a new item, in most cases you can be bold and edit this page. Please read the selected anniversaries guidelines before making your edit. However, if your addition might be controversial, or on a day that is or soon will be on the Main Page, please post your suggestion on the talk page instead.
Please note that the events listed on the Main Page are chosen based more on relative article quality and to maintain a mix of topics, not based solely on how important or significant their subjects are. Only 5–6 events are posted at a time and thus not everything that is "most important and significant" can be listed. In addition, an event is not generally posted this year if it is also the subject of the scheduled April 22, 2017 featured article or the April 22, 2017 featured picture.
To report an error when this appears on the Main Page, see Main Page errors. Please remember that this list defers to the supporting articles, so it is best to achieve consensus and make any necessary changes there first.
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|1529 – Spain and Portugal signed the Treaty of Zaragoza, defining the areas of their respective influence in Asia.||refimprove section|
|1915 – The Germans released chlorine gas as a chemical weapon in the Second Battle of Ypres, killing over 5,000 soldiers within ten minutes by asphyxiation in the first large-scale successful use of poison gas in World War I.||Ypres: multiple issues; chemical weapons in WW1: unreferenced section|
|1945 – About 600 prisoners of the Jasenovac concentration camp in the Independent State of Croatia revolted, but only 80 managed to escape while the other 520 were killed by the Croatian Ustaše regime.||blacklisted URLs, section needs to be rewritten|
|1993 – The first version of Mosaic, created by computer programmers Marc Andreessen and Eric Bina at the National Center for Supercomputing Applications of the University of Illinois at Urbana–Champaign, was released, becoming the first popular web browser and Gopher client.||tagged for expansion|
|2000 – In response to the rapid late 1990s growth of telecommunications, the United Kingdom enacted the Big Number Change, modifying the telephone numbering plans in various areas across the country.||refimprove|
- 1500 – Portuguese explorer Pedro Álvares Cabral and his crew landed in present day Brazil and claimed the land for Portugal.
- 1519 – Spanish conquistador Hernán Cortés established a settlement in Mexico, naming it "Villa Rica de la Vera Cruz" ("Rich village of the True Cross").
- 1864 – The US Congress passed the Coinage Act, authorizing the minting of a two-cent coin, the first U.S. coin to bear the phrase "In God we trust".
- 1930 – France, Italy, Japan, the United Kingdom, and the United States signed the London Naval Treaty, regulating submarine warfare and limiting military ship building.
- 1951 – Korean War: The People's Volunteer Army of China attacked positions occupied mainly by Australian and Canadian forces, starting the Battle of Kapyong.
- 1969 – British yachtsman Sir Robin Knox-Johnston won the Sunday Times Golden Globe Race to complete the first solo non-stop circumnavigation of the world.
- 1983 – The West German news magazine Stern published excerpts from what purported to be the diaries of Adolf Hitler, which were subsequently revealed to be forgeries.
- 1998 – Disney's Animal Kingdom at the Walt Disney World Resort in Florida opened, covering more than 500 acres (2 km2), making it the largest single Disney theme park in the world.
- 2004 – Flammable cargo exploded at Ryongchon Station in Ryongchon, North Korea, killing 160 people.
- 1622 – An Anglo-Persian force combined to take over the Portuguese garrison at Hormuz Island in the Persian Gulf.
- 1889 – Over 50,000 people rushed to claim a piece of the available two million acres (8,000 km2) in the Unassigned Lands, the present-day US state of Oklahoma, entirely founding the brand-new Oklahoma City.
- 1911 – Tsinghua University ("The Old Gate" pictured), one of the leading universities in mainland China, was founded, funded by an unexpected surplus in indemnities paid by the Qing Dynasty to the United States as a result of the Boxer Rebellion.
- 1948 – Civil War in Mandatory Palestine: The Jewish paramilitary group Haganah captured Haifa from the Arab Liberation Army.
- 2000 – In a predawn raid, US Immigration and Naturalization Service agents seized six-year-old Elián González from his relatives' home in Miami, Florida, and returned him to his Cuban father.