William IV Count De Hainault & HOLLAND

William IV Count De Hainault &'s father was Guillaume III De Avesnes Of HAINAULT and his mother was Jeanne DE VALOIS.  His paternal grandparents were John (Jean) I (2Nd Count) DE AVESNES and Philippa DE LUXEMBURG; his maternal grandparents were Charles King De Naples & SICILY and Margaret (Marguerite) DE NAPLES. He had two brothers and four sisters, named John, Louis, Phillipa Of, Isabelle, Joanna and Margaret Countess De Hainault &.