The world's first Global Positioning System (GPS) signal was transmitted from Navigation Technology Satellite 2 (NTS-2) and received at Rockwell Collins in Cedar Rapids, Iowa, at 12:41 a.m. Eastern time (ET).

In a private meeting with U.S. President Ronald Reagan, French President François Mitterrand reveals the existence of the Farewell Dossier, a collection of documents showing the Soviet Union had been stealing American technological research and development.

Franco-Prussian War: France declares war on Prussia.

Opening of the Summer Olympics in Helsinki, Finland.

Field Marshal Ceremony: First occasion in World War II that Adolf Hitler appoints field marshals due to military achievements.

The attempt to install Lady Jane Grey as Queen of England collapses after only nine days.

Great New York City Fire of 1845: The last great fire to affect Manhattan begins early in the morning and is subdued that afternoon. The fire kills four firefighters and 26 civilians and destroys 345 buildings.

Umayyad conquest of Hispania: Battle of Guadalete: Umayyad forces under Tariq ibn Ziyad defeat the Visigoths led by King Roderic.

Representatives of the Iroquois Confederacy sign the Nanfan Treaty, ceding a large territory north of the Ohio River to England.

Italian War of 1542–46: The first Siege of Boulogne begins.

In one of the first militant attacks by Hezbollah, David S. Dodge, president of the American University of Beirut, is kidnapped.

Unsuccessful in his attempt to conquer the Kingdom of Hawaiʻi for the Russian-American Company, Georg Anton Schäffer is forced to admit defeat and leave Kauaʻi.

World War II: Battle of Cape Spada: The Royal Navy and the Regia Marina clash; the Italian light cruiser Bartolomeo Colleoni sinks, with 121 casualties.

World War II: Army order 112 forms the Intelligence Corps of the British Army.

The Troubles: The Provisional Irish Republican Army resumes a ceasefire to end their 25-year paramilitary campaign to end British rule in Northern Ireland.

Spanish Civil War: The CNT and UGT call a general strike in Spain – mobilizing workers' militias against the Nationalist forces.

Wars of Scottish Independence: Battle of Halidon Hill: The English win a decisive victory over the Scots.

Gunmen in Egypt's western desert province of New Valley Governorate attack a military checkpoint, killing at least 21 soldiers. Egypt reportedly declares a state of emergency on its border with Sudan.

Korean politician Lyuh Woon-hyung is assassinated.

A car bomb kills Judge Paolo Borsellino and five members of his escort.