Mortimer credits others for the initial SAS idea, including Colonel Robert Laycock and Stirling’s own brother, Bill. The SAS successfully evaded enemy defences assisted by German-speaking members of the Special Interrogation Group and captured Mersa Sciausc. He spent the rest of the war as a prisoner of war, escaping numerous times before being moved to the supposedly 'escape proof' Colditz Castle.

He told his biographer, Alan Hoe, that it was “a silly show of bravado” and “seemed close to murder”. Both Ritchie and General Sir Claude Auchinleck, the commander in chief of Middle East Command, knew and fought alongside Stirling’s father in the First World War.His biographer Alan Hoe disputed the newspaper's disparaging portrayal of Stirling as a right-wing ' Colonel Blimp'. Further new cast members for series two includePaolo De Vita ( Anonymous, La Grande Guerra del Salento),Anna Manuelli( Blocco 181, Pezzi unici),Edward Bennett( Industry, Save Me Too) andMatteo Franco. Then in December 1955, Stirling heard that Mayne had been killed in a car crash; at last, the chance he'd been waiting for. Operating under the umbrella of a British Army Training Team (BATT), the SAS recruited, trained and commanded the local Firquts. Stirling had been captured in January 1943 and on his release from captivity in April 1945 he assumed he would be welcomed back into the SAS with open arms.

Indeed, while bored in Cairo during the Second World War, Stirling had jumped out of an aeroplane without proper training (or a helmet), tore his parachute on the tail, and hit the ground at such speed he was temporarily blinded and paralysed. He was headhunted by Middle East HQ as an unofficial assistant to Lt-Gen Arthur Smith, Chief of the General Staff, whose boss was General Archibald Wavell, the commander-in-chief, Middle East. Fifty-five men would parachute into the desert and attack five airfields, destroying as many aircraft as they could with Lewes bombs. The Special Raiding Squadron spearheaded the invasion of Sicily Operation Husky and played more of a commando role raiding the Italian coastline, from which they suffered heavy losses at Termoli. His biggest success was on the night of 26–27 July 1942 when his SAS squadron, armed with 18 jeeps, raided the Sidi Haneish landing strip and destroyed 37 Axis aircraft (mostly bombers and heavy transport) for the loss of two men killed.Following a meeting with Major-General Neil Ritchie, the Deputy Chief of Staff, he was granted an appointment with the new Commander-in-Chief Middle East, General Claude Auchinleck. During the mid to late 1970s, Stirling created a secret organisation designed to undermine trades unionism from within. On 8 May 1987, the SAS conducted Operation Judy which resulted in the IRA/ASU [61] suffering its worst single loss of men, when eight men were killed by the SAS while attempting to attack the Loughgall police station.