William III, 1817–90, king of the Netherlands and grand duke of Luxembourg (1849–90), son and successor of William II. William III ruled as a constitutional monarch, and his long reign was unmarred by friction with the States-General. He granted a parliamentary constitution to his Luxembourg subjects and maintained Luxembourg's neutrality in the Franco-Prussian War (1870–71). The leading Dutch statesman during his reign was Jan Thorbecke, who obtained full emancipation of the Dutch Catholics and also promoted economic growth and political reform. With William's death the male Dutch line of the house of Orange-Nassau became extinct. The Netherlands crown passed to his daughter, Wilhelmina, but Luxembourg went to Duke Adolph of Nassau, from a collateral line of the family.