Wikipedia:Selected anniversaries/April 30
April 30: Great Sabbath in Eastern Christianity (2005); Queen's Day in The Netherlands; Walpurgis Night in various European countries.
- 711 - Umayyad troops led by Tariq ibn-Ziyad landed at Gibraltar, beginning the Moorish invasion of Iberia.
- 1789 - George Washington took office as the first President of the United States.
- 1948 - The Organization of American States was established in Bogotá, Colombia.
- 1975 - Reunification Day in Vietnam: North Vietnamese troops captured Saigon, ending the Vietnam War.
- 1993 - CERN announced that the World Wide Web would be free to everyone.