In 1805 Nassau served as high sheriff of Suffolk. He died in Charles Street, Berkeley Square, London, on 18 August 1823, after a paralytic seizure, and was buried in Easton Church, Suffolk, where a monument was erected to his memory.[1]
Book collector
Nassau formed a library, rich in emblem books, early English poetry, and drama. In topography and history his collection comprised many large-paper copies, which had drawings, prints, and portraits added, with rare historical tracts.[1]
Most of Nassau's library was sold by Robert Harding Evans in 1824 in two parts, the first on 16 February and eleven following days, and the second on 8 March and seven following days. The catalogue contained 4,264 lots, and the collection realised the sum of £8,500.[1]