On this day: 20 August

Battle of the Yarmuk: Marking the first great wave of Muslim conquests and the rapid advance of Islam outside Arabia, Arab forces led by Khalid ibn al-Walid defeat the Byzantine Empire and take control of the Levant.

Byzantine–Bulgarian wars: Bulgarian forces led by Tsar Simeon I drove the Byzantines out of Thrace with a decisive victory at the Battle of Achelous.

An army under Isaac I Komnenos defeat forces loyal to rival emperor Michael VI Bringas in the battle of Hades.

The first King of Hungary, Stephen I, and his son, Prince Emeric, are canonized, a date now celebrated as a National Day in Hungary.

At the conclusion of the interrogation of the leaders of the Knights Templar, the three papal investigators, Cardinals Bérenger Frédol, Etienne de Suisy and Landolfo Brancacci, write the "Chinon Parchment", in which they affirm that the accused Templars had confessed, done penance, and were absolved of heresy.

On the third day of battle, philosopher and general Wang Yangming defeats Zhu Chenhao, ending the Prince of Ning rebellion against the reign of the Ming dynasty's Zhengde Emperor.

The Battle of Lens is the last major military confrontation of the Thirty Years' War, contributing to the signing of the Peace of Westphalia in October that year.

War of the Spanish Succession: A Spanish Bourbon army commanded by the Marquis de Bay was soundly defeated by a multinational army led by the Austrian commander Guido Starhemberg.

The Spanish establish the Presidio San Augustin del Tucson in the town that became Tucson, Arizona.

Northwest Indian War: United States troops force the United Indian Nations, a confederacy of Shawnee, Mingo, Lenape, Wyandot, Miami, Odawa, Ojibwe, and Potawatomi warriors, into a disorganized retreat at the Battle of Fallen Timbers.

President Andrew Johnson formally declares the American Civil War over.

Tchaikovsky's 1812 Overture debuts in Moscow, Russia.

Sun Yat-sen, Song Jiaoren, and others establish the Tongmenghui, a Republican, anti-Qing revolutionary organisation, in Tokyo, Japan.

Pluto (pictured) was photographed for the first time at the Yerkes Observatory in Williams Bay, Wisconsin, U.S., 21 years before it was officially discovered by Clyde Tombaugh.

Hurricane-force winds combined hundreds of small fires in the U.S. states of Washington and Idaho into the Devil's Broom fire, which burned about 4,700 square miles (12,100 km²), the largest fire in recorded U.S. history.

World War I: Brussels is captured during the German invasion of Belgium.

The American Professional Football Conference, a predecessor of the National Football League, was established in Canton, Ohio.

The first commercial radio station, 8MK (now WWJ), begins operations in Detroit.

Japan's public broadcasting company, Nippon Hōsō Kyōkai (NHK) is established.

World War II: The Eighth Route Army launches the Hundred Regiments Offensive, a successful campaign to disrupt Japanese war infrastructure and logistics in occupied northern China.

World War II: The Battle of Romania begins with a major Soviet Union offensive.

Hungary adopts the Hungarian Constitution of 1949 and becomes a People's Republic.

Korean War: United Nations forces repelled an attempt by North Korea to capture the city of Taegu.

Senegal breaks from the Mali Federation, declaring its independence.

The NS Savannah, the world's first nuclear-powered civilian ship, embarks on its maiden voyage.

Cold War: Warsaw Pact troops invade Czechoslovakia, crushing the Prague Spring. East German participation is limited to a few specialists due to memories of the recent war. Only Albania and Romania refuse to participate.

Viking program: NASA launches the Viking 1 planetary probe toward Mars.

Voyager program: NASA launches the Voyager 2 spacecraft.

More than 150,000 acres (610 km2) were burned on the worst day of the largest wildfire in the recorded history of Yellowstone National Park in the United States.

Iran–Iraq War: A ceasefire is agreed after almost eight years of war.

The final stage of the O-Bahn Busway in Adelaide, South Australia, was finished, completing at the time the world's longest and fastest guided busway, with buses (example pictured) travelling 12 km (7.5 mi) at speeds of up to 100 km/h (62 mph).

Dissolution of the Soviet Union, August Coup: More than 100,000 people rally outside the Soviet Union's parliament building protesting the coup aiming to depose President Mikhail Gorbachev.

Estonia, occupied by and incorporated into the Soviet Union in 1940, issues a decision on the re-establishment of independence on the basis of legal continuity of its pre-occupation statehood.

In India, Meitei language (officially known as Manipuri language) is included in the scheduled languages' list and made one of the official languages of the Indian Government.

The Supreme Court of Canada rules that Quebec cannot legally secede from Canada without the federal government's approval.

China Airlines Flight 120 catches fire and explodes after landing at Naha Airport in Okinawa, Japan.

Silent Sam, a Confederate monument on the campus of the University of North Carolina at Chapel Hill, was toppled by protestors.

Joe Biden gives his acceptance speech virtually for the 2020 Democratic presidential nomination at the 2020 Democratic National Convention.