In 1940, he was working in Liège, Belgium when the German invasion began. He escaped back to England with British forces in the Dunkirk evacuation. He joined the British Army, being commissioned on the General List. He was subsequently recruited into the Special Operations Executive (SOE) for his language skills and give the code name Hilaire. His brother John Renshaw Starr was also a member of the SOE.
In November 1942, shortly before German forces began their occupation of the Vichy Republic, he arrived secretly by boat on the Mediterranean coast of France. Based in Castelnau-sur-l'Auvignon, posing as a retired Belgian mining Engineer who had made a fortune in the Congo, he successfully organised a French Resistance network in the southwest corner of France, between Toulouse, Bordeaux and the Pyrenees, designated by the SOE as the 'Wheelwright Sector'. Starr spied on the German 11th Tank Division near Bordeaux. The group he led also cut telephone and power lines and sabotaged power stations. He managed to persuade anticommunist and communist resistance member to join forces to fight the German occupiers. One of his team members was Denise Bloch.
In 1944, before the Normandy Invasion, Starr created an armed group called the "Armagnac Battalion" in Toulouse. During the invasion, they destroyed communication and transportation lines. When the SS Panzer division Das Reich tried to reinforce the German forces in Normandy, Starr's troops delayed it so it arrived too late to stop the landings. During the Liberation, Starr's group took control of the Toulouse area. When Charles de Gaulle visited the region, he got into a spirited argument with Starr and threatened to imprison him, until de Gaulle apparent changed his mind and shook Starr's hand. Starr was accused of the torture and brutal treatment of collaborators and prisoners by one of his couriers Anne-Marie Walters. Subsequent investigations established the truth of the accusations but the results of the investigation were hushed up.
Starr died in a hospital in Senlis, France in 1980.
