Wikipedia:Selected anniversaries/May 15
May 15: Independence Day in Paraguay (1811), Teachers' Day in Mexico and South Korea, Nakba Day in Palestinian communities.
- 1525 - Insurgent peasants led by Anabaptist pastor Thomas Muentzer were defeated at the Battle of Frankenhausen, ending the Peasants' War in the Holy Roman Empire.
- 1932 - Prime Minister Inukai Tsuyoshi was assassinated in the May 15 incident, an attempted coup d'état in Japan.
- 1934 - Prime Minister Kārlis Ulmanis dissolved the Saeima and established an authoritarian rule in Latvia.
- 1957 - The United Kingdom tested its first hydrogen bomb in Operation Grapple.
- 1990 - Vincent van Gogh's Portrait of Dr. Gachet (pictured) was sold for US$82.5 million, at the time the world's most-expensive painting.