FERDINAND  ,

duke of Brunswick (1721-1792), Prussian general field marshal, was the fourth son of Ferdinand Albert, duke of Brunswick, and was born at Wolfenbiittel on the 12th of January 1721 . He was carefully educated with a view to a military career, and in his twentieth year he was made chief of a newly-raised Brunswick regiment in the Prussian service . He was present in the battles of Mollwitz and Chotusitz . In sue-cession to Margrave Wilhelm of Brandenburg, killed at Prague (1744), Ferdinand received the command of Frederick the Great's Leibgarde battalion, and at Sohr (1745) he distinguished himself so greatly at the head of his brigade that Frederick wrote of him, " le Prince Ferdinand s'est surpassed' The height which he captured was defended by his brother Ludwig as an officer of the Austrian service, and another brother of Duke Ferdinand was killed by his side in the charge . During the ten years' peace he was in the closest touch with the military work of Frederick the Great, who supervised the instruction of the guard battalion, and sought to make it a model of the whole Prussian army . Ferdinand was, moreover, one of the most intimate friends of the king, and thus he was peculiarly fitted for the tasks which afterwards fell to his lot . In this time he became svcessively major-general and lieutenant-general .