There was little prospect at that time of William’s ever wielding the sceptre, for his elder brother was a strong, healthy lad, and the crown seemed in all human probability likely to descend to him and his heirs. It was important, therefore, for the younger son to choose some vocation which would enable him to be of use to the Fatherland and prove himself worthy of his illustrious ancestors. The Prince’s devoted tutor, Johann Friedrich Gottlieb Delbrück, carefully fed his mind with the history and glories of the house of Brandenburg, a study of which he never tired and to which he applied himself with untiring zeal. Learning from this that a well-disciplined standing army, firmly supported by public sentiment, was the first and most important requisite for the advancement and maintenance of the monarchy, he determined to devote himself to a military career and use all his energy to fit himself for that high and difficult calling, that he might furnish a stout support to his brother’s throne. But he had shown a natural fondness for soldiers at an early age, long before arriving at this maturer resolution, an inclination which his father had carefully encouraged. The two little Princes, with their cousin Frederick, son of the deceased Prince Louis, received their first military instruction in Potsdam from a noncommissioned officer of the first Battalion of the Guard, named Bennstein, and in Berlin from Sergeant Major Cleri of the Möllendorf Regiment. The King was often present at these exercises to note their progress, praise or criticise, and as a reward for their industry, arranged a delightful surprise for them.