OVERVIEW: The Special Air Service (SAS) is an elite British Army special missions unit under UKSF, specializing in counter-terrorism, direct action, special reconnaissance, and hostage rescue. It deploys globally in small, highly trained squadrons capable of covert and rapid-response operations.

DETAILS: Formed in July 1941 by David Stirling as L Detachment for raids behind enemy lines in North Africa, the SAS evolved into 22 Regiment alongside two reserve regiments (21 and 23 SAS). Its structure includes four sabre squadrons (A, B, D, G), each divided into four specialized troops and commanded by a major, with each troop subdivided into four-person patrols. Selection is one of the world’s longest and toughest, including endurance marches (Hills Phase), jungle training, escape-and-evasion, and combat survival, with a pass rate around 10%. Today’s SAS operates through squadrons trained in distinct insertion methods (air, maritime, mobility, mountain), supported by aviation squadron 658 AAC, and its Counter-Terrorism Wing (CTW) maintains national alert readiness from Hereford.

FUNCTION: SAS units conduct high-risk operations such as hostage rescue, counter-terrorism, direct action, long-range reconnaissance, and sabotage, using covert infiltration by air, sea, or land. Missions leverage real-time intelligence, advanced tactics (CQB, sniper, demolitions), and rapid-response support to execute precision operations worldwide.

NOTE:
IOC: July 1941 (SAS origin)
Operators: United Kingdom (part of UKSF)
Structure: 22 SAS (regular), 21 & 23 SAS (reserve); four sabre squadrons, CTW, 658 AAC aviation support, signals & training elements
Base: Stirling Lines, Hereford (headquarters, training ranges including Killing House)
Conflict used in: WWII North Africa/Europe, Malayan Emergency (1948–60), Dhofar Rebellion (1963–76), Northern Ireland (1969–2007), Iranian Embassy Siege (1980), Falklands War (1982), Gulf Wars, Bosnia/Kosovo, Sierra Leone, Afghanistan, Iraq, global CT missions including recent UK homeland operations

SOURCE:
National Army Museum – Special Air Service overview: https://www.nam.ac.uk/explore/SAS ; Britannica – Special Air Service: https://www.britannica.com/topic/Special-Air-Service ; EliteUKForces.info – SAS organisation & operations: https://www.eliteukforces.info/special-air-service/organisation/ ; Wikipedia – Special Air Service: https://en.wikipedia.org/wiki/Special_Air_Service ; Wikipedia – UK Joint Special Forces Selection: https://en.wikipedia.org/wiki/UK_Joint_Special_Forces_Selection ; Wikipedia – Killing House: https://en.wikipedia.org/wiki/Killing_House