Jean-Guillaume de Neubourg-Wittelsbach
Unico Wilhelm van Wassenaer was born in the family castle of Twickel, near Delden, on 30 October 1692, the son of Jacob van Wassenaer Obdam (1645–1714) and Adriana Sophia Raesfelt (died 1694). He grew up in the Hague, where he was taught to play the harpsichord and violin. In 1707-09 he stayed with his father and three sisters in Düsseldorf at the court of Johann Wilhelm, Elector Palatine. The strong Italian influences at the court had a major influence on his musical development.