last king of Yugoslavia, Petar II, was buried in state funeral in Belgrade, Serbia on Sunday. He died 43 years ago in United States. He lived in USA after his family escaped from Nazis in 1941. After World War II, Yugoslavia became communist and its leaders banned him from returning. Petar II died in 1970, aged 47. He was third and last king of Yugoslavia. Three members of his family were buried with him - his wife, Queen Alexandria, his mother Queen Maria, and brother Prince Andrew. Petar II was originally laid to rest in Illinois, USA after he died. His wife was buried in Greece and his mother in cemetery near Windsor Castle in England. The four are now together in their family mausoleum. Petar II became king at age of 11 in 1934 after his father was assassinated in France. He was too young to rule country and waited until he was 17 to be ruler. Eleven days later, he and his family fled to USA after Germany, Bulgaria, Hungary and Italy invaded Yugoslavia. After WWII, Yugoslavia became communist country. Its leader, General Tito, ended country's monarchy. Yugoslavia spilt up following wars that started in 1991. Today, around 40% of Serbs support idea of bringing back monarchy. Milka Radojicic, 78, welcomed back his king, saying: "Our king was forced to leave, he was forced never to set his foot back to his homeland…Finally, he is here where he belongs."