Jean-Guillaume de Neubourg-Wittelsbach
He married the painter Jacoba Maria van Nickelen, with whom he possibly travelled to Dusseldorp to become court painters for Johann Wilhelm, Elector Palatine. According to Jan van Gool he had been the sixth of seven sons and was first apprenticed to a clerk for 8 years before becoming a pupil of Glauber. He and his wife eventually had 8 children, of whom two were still alive when Van Gool was writing; a daughter who was a gifted musician and a son who was a good draughtsman and who designed patterns for silk fabrics. He is not to be confused with Willem Troost (1812-1893).