He participated in the War of the Spanish Succession since 1702 and experienced his trial by fire in the September siege of Venlo.

[1] In the Second Silesian war he was, first, with General Marwitz in Upper Silesia, and then commanded a special corps against the Austrians on 14 February 1745 at Halberschwerdt.

[1] Frederick awarded Lehwaldt the Pour le Mérite in 1742 after the First Silesian War and the Order of the Black Eagle on 4 February 1744.

[2] As political tensions mounted in 1756, Frederick sent Lehwaldt, who commanded of forces in East Prussia, one hundred officers' patents to fill as he saw fit, expecting him to strengthen the army there.

Apraxin retreated from the province after hearing a false report that Empress Elizabeth of Russia had died.

Lehwaldt and Friedrich Wilhelm von Seydlitz, both invalids by that time, were unable to resist the Allied capture and looting of the relatively defenseless Berlin and Potsdam in October 1760 by 15,000 Austrians and 23,600 Russians.