This short piece of work is a summary of the development of anti-aircraft searchlights in France between 1915 and 1918. In 1915 the resources amounted to two sections each with three searchlights, which were employed for the protection of GHQ at St Omer. The narrative describes how the searchlight component of the RE grew (personnel numbered 3,000 all ranks by the end of the war) and notes the different types of projectors in service. It also describes the use of lights, their deployment, their successes and limitations on various parts of the battlefield. It concludes with a section on anticipated development had the war gone on. In the summer of 1940 the responsibility for searchlights passed to the Royal Artillery