Military rank Typical army and marine field officer ranks include colonel , lieutenant colonel, major and, in the British army, captains holding an adjutant's appointment. In many Commonwealth countries the field rank of brigadier is used, although it fills the position held by brigadier general in other countries. Naval and coast guard senior officer ranks include captain and commander. In some countries, the more senior rank of commodore is also included. In others lieutenant-commanders, as equivalents to army and marine majors, are considered senior officers. Commonwealth air force senior officer ranks include group captain, wing commander, and squadron leader, where such ranks
Squadron leader RAF used major as the equivalent rank to squadron leader. Royal Naval Air Service lieutenant-commanders and Royal Flying Corps majors on 31 March 1918 became RAF majors on 1 April 1918. On 31 August 1919, the RAF rank of major was superseded by squadron leader which has remained in continuous usage ever since. Promotion to squadron leader is strictly on merit, and requires the individual to be appointed to a Career Commission, which will see them remain in the RAF until retirement or voluntary resignation. Before the Second World War, a squadron leader commanded a squadron of aircraft. Today, however,