Over the following decades most countries with any substantial military capability established their own independent air forces. The South African Air Force was formed on 1 February 1920 and the Royal Australian Air Force was formed shortly afterwards on 31 March 1921, although it was not until 1922 that the head of the Service was titled as Chief of the Air Staff, placing him on a par with his Australian Army and Navy counterparts. The Canadian Air Force was formed at the end of World War I, and was abolished and reorganized several times between 1918 and 1924. It became the permanent Royal Canadian Air Force when it received the "Royal" title by royal proclamation on 1 April 1924. It did not however become independent of the Canadian Army until 1938 when its head was also designated as Chief of the Air Staff. Similarly, the Royal New Zealand Air Force was established in 1923 as the New Zealand Permanent Air Force but did not become independent of the New Zealand Army until 1937. Other British-influenced countries also established their own independent air forces. For example, the Royal Egyptian Air Force was created in 1937 when Egyptian military aviation was separated from Army command. The Afghan Air Force was established on 22 August 1924, with support from the Soviet Union and Great Britain, but a civil war destroyed most of the planes and it wasn't reestablished until 1937, when King Mohammed Nadir Shah took power.