From 1 September – 7 October 1939 Geyr commanded the 3rd Panzer Division during the invasion of Poland, where it was the most numerically powerful Panzer Division, with 391 tanks.[6] For a victory at Kulm, he was praised by Hitler on the battlefield who had visited the division in recognition for its achievements in Poland.[7] He was promoted to General der Kavallerie of the XXIV Panzer Corps on 15 February 1940. In 1940 he commanded the XXIV Panzer Corps in the Invasion of France.