Roman Emperor Valentinian I made his brother, Flavius Valens, his co-emperor.
Source
The Treaty of Florence was signed, which ended the war between the French Republic and the Kingdom of Naples.
The Vienna Philharmonic Orchestra performed its first concert.
An Imperial Airways passenger aircraft crashed in Belgium, killing all fifteen on board.
Stanley Kramer became the first person to receive a star on the Hollywood Walk of Fame.
The UK issued a new 12-sided £1 coin into circulation.
