Protée served off Morocco in February 1940 before being sent off Turkey in May. She then sailed to Alexandria, where she was immobilised after Operation Catapult until 1943. In July 1943, she joined the Free French Naval Forces and served under Captain Georges Millé, in patrolling off Provence and landing spies in Spain. On 23 November 1943, she torpedoed and sank a 2000-tonne German freighter. She disappeared off Provence on 18 December 1943 with all hands, including three British liaison personnel. Her chief engineer, Louis Laubie, was honoured by having the submarine Laubie named after him.