On 5 June 1753, he became a major and commander of Grenadier Battalion Nr. 4, still in Königsberg. On 13 December 1755, just prior to the outbreak of the Seven Years' War, he became commander of the Fort Friedrichsburg near Königsberg. In 1757, he fought against the invading Russian troops but, after the Battle of Gross-Jägersdorf and a new Russian advance in 1758, he withdrew to the fortress of Kolberg with his troops.