Masters of the continent, the Nazis realized that they would have to defend their gains, and once the United States entered the war, redoubled their efforts. Using forced and slave labor they built a chain of defensive positions, coastal batteries, and beach defenses from the top of Norway to the Franco-Spanish border. However, as was so typical of the Nazis, while the bunkers and batteries seem impressively constructed, and the Atlantic Wall has left a permanent reminder of the years of Nazi domination, it was crippled by lack of strategic planning, internal bickering, and a multitude of command structures that did not communicate with each other effectively. In June 1944 the Allies burst through the wall, and while it took many lives to break the crust of the German defenses, the vaunted Atlantic Wall proved ineffective save for the fortresses the Allies bypassed and subdued later. Using the same formula as in their books on The Normandy Battlefields and Race to the Rhine, Leo Marriott and Simon Forty combine bespoke aerial photography with old photographs, maps, and current illustrations to provide a pictorial analysis of the subject—Around 500 illustrations ensure the subject is well covered.