Wikipedia:Selected anniversaries/May 20
May 20: National Day in Cameroon
- 325 - The First Council of Nicaea was formally opened.
- 1498 - Portuguese explorer Vasco da Gama arrived at Calicut, India.
- 1570 - Abraham Ortelius issued the first modern atlas.
- 1862 - U.S. President Abraham Lincoln signed the Homestead Act into law.
- 1927 - By the Treaty of Jedda, 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.