After the Battle of Falaise, the Germans retreated to Belgium, the Netherlands and Germany. The Allies were once again given ample opportunity to cut off and encircle the German units before they reached the Seine: on August 21, units of the Third Army managed to make a bridgehead over the Seine at Mantes. “Exploitation of this bridgehead down the east bank of the river Seine offered enormous opportunities and the Germans believed that they were so weak on the right bank that this manoeuvre might well have assured the entrapment of the remains of Army Group B in a worse debacle than the Falaise pocket.” But “The allies, however, preferred to try and close the trap by wheeling down the west bank, relying on the speed of their advance and their firepower to close off any crossing points used by the Germans. However, mobility was not their strongest suit, whilst their track record in applying fire power, especially aerial, to the interdiction of ferry routes was not encouraging.”


Their attempts to keep the Germans from transferring units across the Seine proved remarkably ineffective. The result is no surprise: “In the first five days of mass crossings, between 20 and 24 August, the German employed ferries (there were 60 between Elbeuf and the sea), pontoon bridges and improvised rafts, and swimming pure and simple, by which means 25,000 vehicles were ferried to the east bank. Further major crossings took place on the 26th and 27th, at the end of which over 300,000 men were also across. Once again almost all the higher headquarters escaped.” And these last were important because they formed the nucleus around which new unist would be formed.