Wikipedia:Selected anniversaries/March 20
March 20: Vernal equinox and International Earth Day (2005), Palm Sunday in Western Christianity (2005), Independence Day in Tunisia (1956)
- 1413 - Henry V became King of England.
- 1602 - The Dutch East India Company was established.
- 1933 - The construction of the first Nazi German concentration camp at Dachau was completed.
- 1987 - The antiretroviral drug AZT became the first antiviral medication approved for use against HIV and AIDS.
- 1995 - The Aum Shinrikyo sect carried out a poison gas attack on the Tokyo subway system, killing 12 people and injuring more than 6,000 with sarin.