Maurice Southgate was born in 1913 to British parents. Educated in Paris, he attended a technical college and went on to start his own upholstery business. When war came he served with the British Expeditionary Force, and in June 1940 he was evacuated from St Nazaire on the doomed liner Lancastria: attacked by German aircraft on its way to England, it sank with the loss of more than 3000 passengers, though Southgate was able to swim away and was picked up by another vessel. In London he was posted by the RAF to the Air Ministry, but in May 1942 his name passed through to SOE's French Section, and he was accepted for training in July.

Impressed by his serious and thorough approach, Southgate's instructors gave glowing reports on his performance throughout the courses, and he was groomed for the job of organiser for STATIONER, a new circuit which would operate across the Limousin. Parachuting near Clermont-Ferrand in January 1943 with his wireless operator Jacqueline Nearne, he soon built up networks around Châteauroux, Vierzon and Limoges, and also in the far south-west, around Tarbes. By the end of the summer STATIONER had begun to attack railway targets, power stations and aircraft works, and the prospects for more sabotage looked encouraging: in September a courier, Pearl Witherington, arrived to assist, and a month later Southgate was flown back to London to give a report on his progress.

With the knowledge that D-Day could only be a few months away, he returned to continue as organiser, even though the risks he faced were now much greater: the Gestapo had already arrested one of the important Resistance leaders in STATIONER's northern sector, and were keener than ever to catch the circuit's head. Southgate landed safely near Toulouse at the end of January 1944, and immediately found himself burdened with an enormous workload, having to arrange numerous reception committees, fetch and relocate other agents, keep in close contact with his lieutenants and equip maquis units in anticipation of the Allied landings. By April he reported having 2500 men under his control, but on 1 May a Gestapo trap was laid and he was arrested visiting a contact in Montluçon - exhausted by the demands of his responsibilities, Southgate had missed the secret signal showing that the house was not safe. In his absence Pearl Witherington went on to succesfully lead half of the STATIONER circuit, named WRESTLER, while wireless operator Amedée Maingard took the remainder, christened SHIPWRIGHT.

After being beaten by Gestapo interrogators, Southgate was transferred to Avenue Foch headquarters, where he saw another F Section agent, John Starr, who had been caught the previous year: Starr, who had known Southgate before the war, had been kept at Avenue Foch to help their questioning of other captured agents. Southgate was kept at Fresnes prison until August, when he and 36 other agents were deported to Germany, destined for Buchenwald concentration camp. In September sixteen were called to the main gate and executed by hanging, and to avoid the same fate Southgate was admitted to the camp hospital in October through the intervention of Alfred Balachowsky, a prisoner who had formerly been an SOE sub-agent in Paris. Having faked a stomach complaint to get into hospital, Southgate then spent several more weeks being genuinely ill, and after his recovery was moved to work in the tailor's shop. Although he kept a low profile, he was nevertheless forced to hide in the area known as the Little Camp with surviving agents Alfred and Henry Newton, and Christopher Burney when the SS began hunting for them. All four lived to see the liberation of Buchenwald by American forces on 11 April 1945.

F Section's commanding officer, Maurice Buckmaster, considered Southgate to be among the very best of his agents, and he was awarded the DSO for his actions. However, like his comrades, Southgate had been severely affected by his experiences in Buchenwald, and never fully recovered physically or psychologically. He testified at the American war crimes trials at Dachau in 1947, and returned to work in the furniture business. He died near Paris in March 1990.