Maurice, Prince of Orange
Many have erroneously interpreted these developments as the office of the stadtholder (at least in Holland and Zeeland) becoming "monarchical". That would be a misunderstanding, however, even though the court of the stadtholder took on a decidedly "princely" aspect (as it had done under William's grandfather Frederick Henry, Prince of Orange). If William was a monarch at all, it was a "constitutional" one, with still sharply limited powers, formally and politically. The States-General remained sovereign in the Republic, the entity with which other states concluded treaties and made war or peace. The pretensions to sovereign supremacy of the provinces, however, as under the De Witt regime, were again replaced with the constitutional theory of Maurice, Prince of Orange, after his overturning of the regime of Johan van Oldenbarnevelt in 1618, in which the provinces were at least in certain respects subservient to the "Generality".