The new Prince of Orange succeeded to a difficult position, but he was endowed with all the qualities of a real leader of men. Forty-one years old and brought up from boyhood in camps under the eye of his brother, Frederick Henry was now to show that he was one of the most accomplished masters of the military art, and especially siege-craft, in an age of famous generals, for Bernard of Saxe-Weimar, Torstenson, Turenne, Charles Gustavus and the Great Elector were all trained in his school. He was, however, much more than an experienced and resourceful commander in the field. He inherited much of his father’s wary and tactful statesmanship and skill in diplomacy. He was, moreover, deservedly popular. He was a Hollander born and bred, and his handsome face, chivalrous bearing, and conciliatory genial temper, won for him an influence, which for some years was to give him almost undisputed predominance in the State. To quote the words of a contemporary, Van der Capellen, “the prince in truth disposed of everything as he liked; everything gave way to his word.”
The offices and dignities held by Maurice were at once conferred on Frederick Henry. He was elected Stadholder of Holland, Zeeland, Utrecht, Gelderland and Overyssel, and was appointed Captain-General and Admiral-General of the Union and head of the Council of State. During practically the whole of his life the prince spent a considerable part of the year in camp, but he was able all the time to keep in touch with home affairs, and to exercise a constant supervision and control of the foreign policy of the State by the help of his wife, and through the services of Francis van Aerssens. The Court of the Princess of Orange, graced as it was by the presence of the exiled King and Queen of Bohemia, was brilliant and sumptuous, and gave to the reality of power possessed by the stadholder more than a semblance of sovereign pomp. During her husband’s absence she spared no pains to keep him well-acquainted with all the currents and under-currents of action and opinion at the Hague, and was not only able to give sound advice, but was quite ready, when necessity called, to meet intrigue with intrigue and render abortive any movements or schemes adverse to the prince’s policy or authority. The obligations of Frederick Henry to Aerssens were even greater. The stadholder was at first suspicious of the man, whom he disliked for the leading part he had taken against Oldenbarneveldt. But he did not allow personal prejudice to prevent him from employing a diplomatist of Aerssens’ experience and capacity, and, with acquaintance, he learned to regard him, not merely as a clever and wise councillor, but as a confidential friend.