Peter Karadjordjevic, II, Yugoslavian Monarch and Last King of Yugoslavia, was born September 6, 1923. He became King of Yugoslavia at the age of 11 in 1934, after his father, Alexander I was assassinated in Marseilles, France. The country was ruled until 1941 by Prince Paul, a regent, when Peter began his rule. His rule was short-lived when the Nazis overran the country that same year. Peter went to London, where he headed a government in exile.