Historical Events on May 15

21 significant historical events occurred on May 15. On May 15, several important historical events have occurred in politics, sports, and international relations. In 1934, Latvian Prime Minister Kārlis Ulmanis led a coup d'état. In 1955, the Austrian State Treaty was signed, establishing Austria's international status. Tragically, in 1974, the Ma'alot massacre took place in Israel, involving Palestinian militants. The date has also seen significant sporting events like the 1974 European Cup Final and the 1988 Monaco Grand Prix.