Operation Diadem was the final battle for Monte Cassino the plan was the U.S. II Corps on the left would attack up the coast along the line of Route 7 towards Rome. The French Expeditionary Corps (CEF) to their right would attack from the bridgehead across the Garigliano into the Aurunci Mountains. British XIII Corps in the centre right of the front would attack along the Liri valley whilst on the right 2nd Polish Corps would isolate the monastery and push round behind it into the Liri valley to link with XIII Corps. I Canadian Corps would be held in reserve ready to exploit the expected breakthrough. Once the German Tenth Army had been defeated, the U.S. VI Corps would break out of the Anzio beachhead to cut off the retreating Germans in the Alban Hills.