The cultured Grumbkow was born in Berlin as the son of Joachim Ernst von Grumbkow, General War Minister of Brandenburg-Prussia. Educated in France, he married a Mademoiselle de la Chevalerie. He took part in the War of the Spanish Succession, fighting in the Battle of Malplaquet and reaching the rank of Generalmajor. Frederick eventually reached a reconciliation with both Frederick William and Grumbkow. He referred to Grumbkow as "the Cassubian", because of his Pomeranian ancestry. Grumbkow died in Berlin in 1739.