Which country does the SAS special unit come from?

The Special Air Service (SAS) is a special forces unit of the British Army. The SAS was founded in 1941 as a regiment, and later reconstituted as a corps in 1950. The unit undertakes a number of roles including covert reconnaissance, counter-terrorism, direct action and hostage rescue. Much of the information and actions regarding the SAS is highly classified, and is not commented on by the British government or the Ministry of Defence due to the sensitivity of their operations.