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
Provisional Government of the French Republic on 3 June 1944, the day before Charles de Gaulle arrived in London from Algiers on Winston Churchill's invitation, and three days before D-Day. The CFLN itself had been created exactly one year earlier through the uniting of de Gaulle's ("Comité national français", or CNF) and Henri Giraud's organisations. Among its most immediate concerns were to ensure that France did not come under allied military administration, preserving the sovereignty of France and freeing allied troops for fighting on the front. After the liberation of Paris on 25 August 1944, it moved back to the capital, establishing a new "national unanimity"