1257 - Kraków, Poland, receives city rights.
1799 - Naturalists Alexander von Humboldt and Aimé Bonpland set sail in the Pizarro from A Coruña and begin their 5 year Latin American expedition.
1805 - 1st recorded tornado in "Tornado Alley" (Southern Illinois).
1806 - Batavian Republic becomes Kingdom of Holland.
1849 - Danish National Day-Denmark becomes a constitutional monarchy.
1873 - Sultan Bargash closes slave market of Zanzibar.
1972 - UN Conference on Human Environment opens in Stockholm.
WORLD ENVIRONMENT DAY.
