During the War of the Bavarian Succession in 1778 - 79 , he acted as a volunteer in the army of Frederick the Great .
During the War of the Bavarian Succession in 1778 - 79 , he gained the trust of the Prussian king .
During the War of the Bavarian Succession in 1778 - 79 , he acted as a volunteer in the army of Frederick the Great and gained the trust of the Prussian king .