The House of Nassau-Weilburg, a branch of the House of Nassau, ruled a division of the County of Nassau, which was a state in what is now Germany, then part of the Holy Roman Empire, from 1344 to 1806. On 17 July 1806, upon the dissolution of the Holy Roman Empire, the principalities of Nassau-Usingen and Nassau-Weilburg both joined the Confederation of the Rhine. Under pressure from Napoleon, both principalities merged to become the Duchy of Nassau on 30 August 1806, under the joint rule of Prince Frederick August of Nassau-Usingen and his younger cousin, Prince Frederick William of Nassau-Weilburg. As Frederick August had no heirs, he agreed that Frederick William should become the sole ruler after his death. However, Frederick William died from a fall on the stairs at Schloss Weilburg on 9 January 1816 and it was his son William who later became duke of a unified Nassau. The sovereigns of this house afterwards governed the Duchy of Nassau until 1866. Since 1890, they have reigned over the Grand Duchy of Luxembourg. Religion The first two Grand Dukes of Luxembourg, Adolphe and Guillaume IV, were Protestants, however, the Christian denomination of the house changed after Grand Duke Guillaume IV's marriage to Marie Anne de Braganza, who was Roman Catholic. Gallery Sovereigns from the House of Nassau-Weilburg Nassau Counts of Nassau-Weilburg 1344–71: John I 1371–1429: Philip I 1429–42: Philip II and John II 1442–92: Philip II 1492–1523: Louis I 1523–59: Philip III 1559–93: Albrecht 1559–1602: Philip IV 1593–1625: Louis II 1625–29: William Louis, John IV and Ernst Casimir 1629–55: Ernst Casimir 1655–75: Frederick 1675–88: John Ernst Princely counts of Nassau-Weilburg 1688–1719: John Ernst 1719–53: Charles August 1753–88: Charles Christian 1788–1816: Frederick William 1816: William Dukes of Nassau 1816–39: William 1839–66: Adolphe Grand Dukes of Luxembourg 1890–1905: Adolphe 1905–12: William IV 1912–19: Marie-Adélaïde 1919–64: Charlotte 1964–2000: Jean 2000–present: Henri <div style="overflow:auto"> Family Tree References |- German noble families Luxembourgian noble families Counties of the Holy Roman Empire 1340s establishments in the Holy Roman Empire 1344 establishments in Europe