Wikipedia:Selected anniversaries/January 21
January 21: Martin Luther King Day in the United States (2008).
- 304 – Saint Agnes was executed for refusing the prefect Sempronius' wish for her to marry his son. She is today the patron saint of girls, chastity, virgins, and others.
- 1525 – The Anabaptist Movement was born when founders Conrad Grebel, Felix Manz, and George Blaurock re-baptized each other and other followers in Zürich, Switzerland, believing that the Christian religious practice of infant baptism is invalid because a child cannot commit to a religious faith.
- 1793 – French Revolution: After being found guilty of treason by the National Convention, King Louis XVI (pictured) was guillotined in front of a cheering crowd at the Place de la Révolution in Paris.
- 1919 – The First Dáil Éireann first convened at the Mansion House in Dublin, adopting a Declaration of Independence calling for a new sovereign state: the Irish Republic.
- 1968 – Vietnam War: The Vietnam People's Army attacked Khe Sanh Combat Base, a U.S. Marines outpost in Quang Tri Province, South Vietnam, starting the Battle of Khe Sanh.
More anniversaries: