Empire ship the Normandy invasion depended on the successful construction of the Mulberry ports. These were prefabricated ports, constructed at Southampton, Gosport, Portsmouth, Tilbury Docks, and even as far north as Birkenhead and Hartlepool. Two hundred tugs then took three months to tow the components of the harbours from where they were constructed to assembly areas on the South Coast. Between 7 June 1944 and the end of July, the tugs towed the materials across the channel to Normandy. Before D-Day, sixty old merchant ships and four old warships were selected as blockships, to be scuttled in a line to give protection
French Forces of the Interior General Marie Pierre Kœnig, who attempted to unify resistance efforts against the Germans. General Eisenhower confirmed Koenig's command of the FFI on 23 June 1944. The FFI were mostly composed of resistance fighters who used their own weapons, although many FFI units included former French soldiers. They used civilian clothing and wore an armband with the letters "F.F.I." According to General Patton, the rapid advance of his army through France would have been impossible without the fighting aid of the FFI. General Patch estimated that from the time of the Mediterranean landings to the arrival of U.S. troops at Dijon,