princely dynasty that derived its name from the medieval principality of Orange, in old Provence in southern France. The dynasty was important in the history of The Netherlands and is that nation's royal family.

The counts of Orange became independent upon the disintegration of the feudal kingdom of Arles. They were vassals of the Holy Roman emperors from the 12th century, and they early began to style themselves princes. When Philibert de Chalon, prince of Orange, died in 1530, he was succeeded by his sister Claudia's son René of Nassau, who in 1538 succeeded his father, Henry III of Nassau-Dillenburg-Breda, not only in his German patrimony but also in scattered possessions in the Netherlands. Dying in 1544, René bequeathed his titles to his young cousin, William I of Nassau-Orange.

Known as William I the Silent, the prince of Orange led the Netherlands' revolt against Spain from 1568 to his death in 1584 and held the office of stadtholder in four of the rebelling provinces. This was the start of a tradition in the Dutch Republic whereby the stadtholderships were for long periods monopolized by the princes of Orange and counts of Nassau, supported by an enduring Orange “party” composed of nobles, orthodox Calvinist leaders, artisans, and peasants against the rivalry of the patriciate of Holland. The gifted 16th- and 17th-century stadtholders were followed by less effective Orange leaders in the 18th century. The last stadtholder fled to England in 1795 as the republic collapsed.

His son, the next titular prince of Orange, became sovereign prince of The Netherlands in 1814 and king in 1815, as William I. He and his successors, William II and William III, were also grand dukes of Luxembourg; and the title prince of Orange was borne by heirs apparent to the Dutch throne. With King William III the male line died out in 1890; but the Dutch queen Wilhelmina decreed in 1908 that her descendants should be styled princes and princesses of Orange-Nassau. See also Nassau.