In August 1942, the Allies launched a raid against the German-held port of Dieppe on the French channel coast. It was largely a disaster, with the Canadian forces bearing the brunt of the catastrophe.
However, it wasn't all a failure. Landings against nearby gun batteries by 4 Commando proved an excellent demonstration of the military adage "train hard, fight easy" and the advantage of proper planning.
Interestingly, this successful raid also included members of the Free French and US Commandos, later named the US Rangers, and it included the first US land forces to engage the Germans on mainland Europe.
Written with the assistance of veterans who survived the raid and subsequent commando operations, this is a compelling read.