In early 1944, the British Prime Minister Winston Churchill applied strong pressure on Peter to dismiss his prime minister, Božidar Purić, whom almost everybody viewed as incompetent, and to sever his links with General Mihailović, whom Churchill was convinced by this point was a collaborator. At the same time, the British threatened to stop arms shipments to Josip Broz Tito's Partisans unless he recognized King Peter as the rightful king of Yugoslavia. Churchill wanted to preserve the Yugoslav monarchy to keep the country in the western sphere of influence after the war while incorporating the Partisans into the royalist government-in-exile. Peter married Alexandra in London on 20 March 1944. Attending the wedding which was held at the Yugoslav legation in London was King George VI who served as Peter's best man together with King Haakon VII of Norway, King George II of Greece, and Queen Wilhelmina of the Netherlands all attending. They had one son, Crown Prince Alexander, who was born on 17 July 1945.