Independence Day in Jordan (1946); Liberation Day in Lebanon (2000); African Liberation Day in various African countries

• 1521 – Martin Luther was declared an outlaw and a heretic by the Diet of Worms.
• 1810 – May Revolution: The Primera Junta, the first independent government in Argentina, was established in Buenos Aires.
• 1946 – Abdullah bin Husayn (pictured), Emir of the Emirate of Transjordan, was proclaimed King of the renamed "Hashemite Kingdom of Transjordan".
• 1961 – Project Apollo, with "the goal, before this decade is out, of landing a man on the Moon and returning him safely to the Earth" was announced.
• 1966 – The first prominent DaZiBao during the Cultural Revolution in China was posted at Peking University.