Born in Montenegro, he was the son of Peter I, who took power in Serbia in 1903 during a violent coup. He was actually the second son and thus not the heir to his father, but his brother George decided to renounce his position, so Alexander was next in line. He served in the Balkan wars of 1912, and in 1914 was named regent.
As WWI broke out, he became Commander in Chief, and as the war ended and the Kingdom of Serbs, Croats and Slovenes came into existence, he was named king in 1921 following a short period of rule by his father. In 1929, he abolished the constitution and proclaimed a dictatorship in an effort to keep the peace in his ethnically tense nation. With the public clamoring for a return to a democratic regime, he was assassinated in 1934 by a Macedonian who was reportedly backed by Croat separatists.
Gavrilo was a Serb who joined the secretive Black Hand society, a strongly nationalistic group. He was one of seven men who lined the streets where Arch Duke Ferdinand's procession was to travel on a visit to Sarajevo, but the first to throw a grenade. It bounced out of the car, which sped away.
Later that day, Ferdinand was en route to the hospital to visit two people injured by the errant grenade and he happened to drive right by Ferdinand, who was sitting at a street café. He shot Ferdinand several times from five feet away, and he and his wife were both killed. Princip was arrested before he could kill himself, as per his instructions, and was sentenced to 20 years in prison. He died of tuberculosis before the end of his sentence.
Peter II was the son of Alexander and the last king of Yugoslavia. He came to power following his father's assassination and was the leader of Yugoslavia during WWII. In April of 1941, German forces attacked Yugoslavia, and on the 17th, Peter's government fled the country. After the war, while still in exile, Peter II was deposed, and Tito's party came into power.
