Dutch Frederik Hendrik
born Jan. 29, 1584, Delft, Holland
died March 14, 1647, The Hague
Third hereditary stadtholder (1625–47) of the Dutch Republic .
He succeeded his half brother, Maurice of Nassau , as prince of Orange and count of Nassau. Like his father, William I , Frederick Henry continued the war of independence against Spain. By establishing hereditary succession to the stadtholdership for the house of Orange , he exercised semimonarchical powers. A successful strategist, he was responsible for the United Provinces' foreign policy, beginning negotiations that led to a favourable treaty with Spain in 1648.