B軍集団
Shortly after the conquest of Poland, on 12 October 1939 Bock was given command of Army Group B, with 29½ divisions, including three armoured divisions. These were tasked with advancing through the Low Countries and luring the northern units of the Allied armies into a pocket. Army Group B consisted of the 18th and 6th Armies. While his units were overrunning the Netherlands, in May 1940, Bock attempted to call on the exiled former "Kaiser"—Wilhelm II—at Doorn, but Bock was unable to gain admittance, the German troops guarding the residence having been instructed to prevent such visits.