Belgian forces took control of Rwanda and Burundi during World War I, with Kigali being captured by the Northern Brigade led by Colonel Philippe Molitor on 6 May 1916. The Belgians were granted sovereignty by a League of Nations mandate in 1922, forming the mandatory territory of Ruanda-Urundi. In early 1917, Belgium attempted to assert direct rule on the mandate, placing King Musinga under arrest and sidelining Rwandans in the judiciary. In this period, Kigali was one of two provincial capitals, alongside Gisenyi. An agricultural-labour shortage caused by the recruitment of locals to assist the European armies during the war, the plundering of food by soldiers, and torrential rains which destroyed crops, led to a severe famine at the start of the Belgian administration. The famine, combined with the difficulty of governing the complex Rwandan society, prompted the Belgians to re-establish the German-style indirect rule at the end of 1917. Musinga was restored to his throne at Nyanza, with Kigali remaining home to the colonial administration. This arrangement persisted until the mid-1920s, but from 1924 the Belgians began once more to sideline the monarchy, this time permanently. Belgium took over control of dispute resolution, appointment of officials and collection of taxes. Kigali remained relatively small through the remainder of the colonial era, as much of the administration took place in Ruanda-Urundi's capital Usumbura, now known as Bujumbura in Burundi. Usumbura's population exceeded 50,000 during the 1950s and was the mandate's only European-style city, while Kigali's population remained at around 6,000 until independence in 1962.