Duchy of Nassau

The Duchy of Nassau (German: Herzogtum Nassau), was a German state within the Confederation of the Rhine and later in the German Confederation. The male line of its ruling dynasty, now extinct, was the House of Nassau.

History
On 17th July 1806, the remaining counties of Nassau-Usingen and Nassau-Weilburg joined the Confederation of the Rhine. Under pressure from Napoleon I both counties merged to form the Duchy of Nassau on 30th August 1806, under the joint rule of Frederick Augustus, and his younger cousin Frederick William. As Frederick August had no heirs, he agreed that Frederick William should become sole ruler after his death. However Frederick William died from a fall on the stairs, at Weilburg Castle on 9th January 1816 and it was his son William who became Duke of Nassau.

At the 1815 Congress of Vienna, the Principality of Orange-Nassau was incorporated into the Duchy of Nassau and subsequently the unified Duchy joined the German Confederation with Wiesbaden as its new capital. Through the extinction of most lines, the Nassau-Usingen branch of the Nassau-Weilburg line under Duke William became the reigning house of Nassau until the Austro-Prussian War in 1866, when it was annexed by the Kingdom of Prussia and incorporated into the Province of Hesse-Nassau. William's son Adolphe,the last Duke of Nassau, received Luxembourg after the male line of Nassau-Dillenburg became extinct in 1890.

Nassau (land) 拿騷 (國)