March 21: Independence Day in Namibia (1990); Naw-Rúz in the Bahá’í calendar; World Down Syndrome Day; Mother’s Day in the Arab world
- 1909 – The remains of the Báb, one of three central figures of the Bahá’í Faith, were interred by `Abdu’l-Bahá in Haifa, present-day Israel.
- 1943 – World War II: Wermacht officer Rudolf Christoph von Gersdorff (pictured) attempted to assassinate Adolf Hitler by suicide bombing, but had to abort the plan at the last minute.
- 1946 – The Los Angeles Rams of the National Football League signed Kenny Washington, making him the first African American player in the league since 1933.
- 2002 – British schoolgirl Amanda Dowler was abducted on her way home from Heathside School in Walton-on-Thames, Surrey.
- 2006 – A man using a hammer smashed the statue of Phra Phrom in the Erawan Shrine in Bangkok, Thailand, and was subsequently beaten to death by bystanders.