Frederick William died in January 1816, only two months before his cousin.

Frederick William was the eldest surviving son of Karl Christian of Nassau-Weilburg and Princess Wilhelmine Carolina of Orange-Nassau.

Anne was in turn the eldest daughter of George II of Great Britain and Caroline of Ansbach.

On 31 July 1788 in Hachenburg, Frederick William married Burgravine Louise Isabelle of Kirchberg (Hachenburg, 19 April 1772 – Vienna, 6 January 1827).

His father died on 28 November of the same year and Frederick William succeeded him.