On August 20:
636 Battle of Yarmouk: Arab forces led by Khalid ibn al-Walid took control of Syria and Palestine , marking the first great wave of Muslim conquests and the rapid advance of Islam outside Arabia.
917 Battle of Acheloos: Tsar Simeon I of Bulgaria decisively defeated a Byzantine army.
1000 The foundation of the Hungarian state by Saint Stephen.
1083 Canonization of the first King of Hungary, Saint Stephen and his son Saint Emeric.
1391 Konrad von Wallenrode became the 24th Hochmeister of the Teutonic Order.
1672 Former Grand Pensionary Johan de Witt and his brother Cornelis were murdered by an angry mob in The Hague.
1778 Bernardo O’Higgins, South American revolutionary, was born (d. 1842).
1794 Battle of Fallen Timbers – American troops forced a confederacy of Shawnee, Mingo, Delaware, Wyandot, Miami, Ottawa, Chippewa, and Potawatomi warriors into a disorganised retreat.
1804 Lewis and Clark Expedition: the “Corps of Discovery”, exploring the Louisiana Purchase, suffered its only death when sergeant Charles Floyd died, apparently from acute appendicitis.
1858 Charles Darwin first published his theory of evolution in The Journal of the Proceedings of the Linnean Society of London, alongside Alfred Russel Wallace’s same theory.
1866 President Andrew Johnson formally declared the American Civil War over.
1882 Peter Ilyich Tchaikovsky’s 1812 Overture debuted in Moscow.
1888 Mutineers imprisoned Emin Pasha at Dufile.
1900 Japan’s primary school law was amended to provide for four years of mandatory schooling.
1923 Jim Reeves, US country music singer, was born (d.1964).
1926 Japan’s public broadcasting company, Nippon Hōsō Kyōkai (NHK) was established.
1927 Yootha Joyce, English actress, was born (d. 1980).
1940 The New Zealand Shipping Company freighter Turakina was sunk by the Orion 260 nautical miles west of Taranaki, following a brief gun battle – the first ever fought in the Tasman Sea. Thirty-six members (some sources say 35) of its largely British crew were killed. Twenty survivors, many of them wounded, were rescued from the sea and taken prisoner.
1940 In Mexico City exiled Leon Trotsky was fatally wounded with an ice axe by Ramon Mercader.
1941 Dave Brock, British musician and founder of Hawkwind, was born.
1941 Slobodan Milošević, President of Serbia and of Yugoslavia (d. 2006).
1944 Rajiv Gandhi, Prime Minister of India, was born (d. 1991).
1944 – 168 captured allied airmen, accused of being “terror fliers”, arrive at Buchenwald concentration camp. The senior officer was Phil Lamason of the RNZAF.
1944 The Battle of Romania began with a major Soviet offensive.
1948 Robert Plant, British Musician (Led Zeppelin), was born.
1955 In Morocco, a force of Berbers raided two rural settlements and killed 77 French nationals.
1960 Senegal broke from the Mali federation, declaring its independence.
1974 Amy Adams, American actress, was born.
1975 NASA launched the Viking 1 planetary probe toward Mars.
1977 NASA launched Voyager 2.
1979 The East Coast Main Line rail route between England and Scotland was restored when the Penmanshiel Diversion opens.
1982 Lebanese Civil War: a multinational force landed in Beirut to oversee the PLO’s withdrawal from Lebanon.
1988 “Black Saturday” of the Yellowstone fire in Yellowstone National Park.
1988 – Iran–Iraq War: a cease-fire was agreed after almost eight years of war.
1989 The pleasure boat Marchioness sank on the River Thames following a collision, 51 people were killed.
1989 The O-Bahn in Adelaide, the world’s longest guided busway, opened.
1991 August Coup: more than 100,000 people rallied outside the Soviet Union’ss parliament building protesting the coup aiming to depose President Mikhail Gorbachev.
1991 Estonia seceded from the Soviet Union.
1993 The Oslo Peace Accords were signed.
1997 Souhane massacre in Algeria; more than 60 people were killed and 15 kidnapped.
1998 The Supreme Court of Canada ruled that Quebec couldn’t legally secede from Canada without the federal government’s approval.
1998 The United States military launched cruise missile attacks against alleged al-Qaida camps in Afghanistan and a suspected chemical plant in Sudan in retaliation for the August 7 bombings of American embassies in Kenya and Tanzania.
2008 – Spanair Flight 5022, from Madrid to Gran Canaria, skids off the runway and crashes at Barajas Airport. 146 people are killed in the crash, 8 more died afterwards. Only 18 people survived.
Sourced from NZ History Online & Wikipedia