Field Marshal Walther Model’s Army Group B would be responsible for the attack. His forces included Generaloberst Josef “Sepp” Dietrich’s Sixth Panzer Army, the largest and best equipped of the three striking armies, which was to drive northward, quickly cross the Meuse River and capture Amsterdam before the surprised Allies could regroup. Directly to the south of this force General der Panzertruppen Hosso-Eccard von Manteufel’s Fifth Panzer Army would push west in support of Dietrich’s attack. General der Panzertruppen Erich Brandenburger’s Seventh Army would protect the southern flank. The build-up was given the defensive-sounding codename Watch on the Rhine. Strict security measures included no radio communication to prevent Allied radio intercepts. (Map by Petho Cartography)