After the Allied landings at Normandy, the Germans began a counter-offensive to overwhelm the landing force with armoured attacks but these failed for lack of co-ordination and Allied superiority in anti-tank defence and in the air. The most notable attempt to use deep penetration operations in Normandy was Operation Luttich at Mortain, which only hastened the Falaise Pocket and the destruction of German forces in Normandy. The Mortain counter-attack was defeated by the US 12th Army Group with little effect on its own offensive operations.