Wikipedia:Selected anniversaries/May 20
May 20: National Day in Cameroon (1972), Independence Day in East Timor (2002)
- 325 - The First Council of Nicaea, the first ecumenical council of the Christian Church, was formally opened in present-day Iznik, Turkey.
- 1570 - Cartographer Abraham Ortelius issued the first modern atlas.
- 1862 - U.S. President Abraham Lincoln (pictured) signed the Homestead Act into law, which gave the right to claim freehold title to 160 acres (65 hectares) of undeveloped land in the American West.
- 1927 - By the Treaty of Jeddah, the United Kingdom recognized the sovereignty of King Ibn Saud in the Kingdoms of Hejaz and Nejd, which later merged to become the Kingdom of Saudi Arabia.
- 2002 - East Timor became the first new sovereign state of the twenty-first century.