1386: Treaty of Windsor between Portugal and England is ratified at Windsor, cementing and strengthening ties between the two kingdoms. The treaty guarantees the mutual security of both nations and strengthens commercial ties. It is the oldest diplomatic alliance still in force.

1865: President Andrew Johnson issues a proclamation declaring that armed resistance in the South is virtually at an end, the commonly accepted end date of the American Civil War

1901: First Australian Parliament opens in Melbourne, though the first working session is not until May 21

1941: British intelligence at Bletchley Park breaks German spy codes after capturing Enigma machines aboard the weather ship München

1945: Soviet Union celebrates Victory Day in World War II

1960: United States becomes the first country to legalize the birth control pill

Source: Onthisday.com