The Special Air Service (SAS) is a special forces unit of the British Army, founded in 1941. The unit undertakes a number of roles including covert reconnaissance, counter-terrorism, direct action and hostage rescue. The corps currently consists of the 22nd Special Air Service Regiment (22 SAS), the regular component under the operational command of United Kingdom Special Forces, as well as the 21st (Artists) Special Air Service Regiment (Reserve) (21 SAS) and the 23rd Special Air Service Regiment (Reserve) (23 SAS), which are reserve units.