Peter II of Yugoslavia

Peter Karađorđević became King of Yugoslavia in October 1934 when his father, Alexander I, was assassinated in Marseille; he was eleven, so his cousin Prince Paul ruled as regent. In late March 1941, after Paul signed Yugoslavia into the Tripartite Pact, a pro-British coup deposed the regent and declared Peter of age. Ten days later, Axis forces invaded and overran the country, forcing the teenage king and his government into exile. Peter set up a government-in-exile in London in June 1941, married Princess Alexandra of Greece and Denmark in March 1944, and had a son, Alexander, a year later. In November 1945, the Yugoslav Constituent Assembly formally deposed him and declared a republic. He settled in the United States, battled depression and alcoholism, and died of cirrhosis in November 1970 at forty-seven - buried in Illinois, then returned to the Royal Mausoleum of Oplenac in 2013.