Lieutenant-Colonel 'Paddy' Blair Mayne was one of Stirling's first recruits into the SAS. The nickname 'Paddy' came from his Irish ancestry, and before the war he was well known as an international rugby player. In battle, he possessed qualities in leadership that set him apart from most men. With a reputation of bravery, which was sometimes characterised as reckless and wild.

Mayne joined L Detachment SAS Brigade on its formation in July 1941 and played a major role in operations during the North African campaign. On the unit's expansion as 1st SAS Regiment (1 SAS), he commanded A Squadron. After David Stirling's capture on 27 January 1943, Mayne was promoted to Lieutenant-Colonel and assumed command of the Regiment until its reorganisation into two separate units, the Special Raiding Squadron and the Special Boat Section. Mayne subsequently commanded the SRS throughout operations in Sicily and Italy and by the time the campaign ended he had been awarded the the bar for his previously awarded DSO.

In March 1944 the SRS returned to England where it was expanded and reverted to it's old designation as 1 SAS, joining the newly formed SAS Brigade. Mayne continued in command of the regiment during operations in France, the Low Countries, Scandinavia and Germany, subsequently being awarded more bars to his DSO. On October 1 1945 the SAS were disbanded and shortly afterwards Paddy Mayne was demobilised and returned to civilian life. Ten years later, on 15 December 1955, he was killed in a traffic accident in Newtownards, Northern Ireland.