Peter II Karađorđević was the last king of Yugoslavia, reigning from October 1934 until he was deposed in November 1945. He was the last reigning member of the Karađorđević dynasty.

The Yugoslav coup d'état took place on 27 March 1941 in Belgrade, Kingdom of Yugoslavia, when the regency led by Prince Paul of Yugoslavia was overthrown and King Peter II fully assumed monarchical powers. The coup was planned and conducted by a group of pro-Western Serbian-nationalist Royal Yugoslav Air Force officers formally led by the Air Force commander, General Dušan Simović, who had been associated with several putsch plots from 1938 onwards. Brigadier General of Military Aviation Borivoje Mirković, Major Živan Knežević of the Yugoslav Royal Guards, and his brother Radoje Knežević were the main organisers in the overthrow of the government. In addition to Radoje Knežević, some other civilian leaders were probably aware of the takeover before it was launched and moved to support it once it occurred, but they were not among the organisers. Peter II himself was surprised by the coup, and heard of the declaration of his coming-of-age for the first time on the radio.