March 12: Independence Day in Mauritius (1968); Arbor Day in China and Taiwan
- 515 BCE – Construction of the Temple in Jerusalem was completed.
- 538 – Vitiges, king of the Ostrogoths, ended his siege of Rome, leaving the city in the hands of the victorious Roman general, Belisarius.
- 1622 – Ignatius of Loyola and Francis Xavier, founders of the Jesuits, were canonized as saints by Pope Gregory XV.
- 1930 – Gandhi began the Dandi March (pictured), a 24-day walk to defy the British tax on salt in colonial India.
- 1947 – Cold War: U.S. President Harry S. Truman proclaimed the Truman Doctrine to help stem the spread of Communism.
- 1971 – The Turkish Armed Forces executed a coup by memorandum, forcing the resignation of Prime Minister Süleyman Demirel.