Mahaut married Guillaume II DE NEVERS Count of Tonnerre, son of Guillaume I DE NEVERS Count of Nevers & Auxerre and Ermengarde DE TONNERRE. (Guillaume II DE NEVERS Count of Tonnerre was born about 1050 in Nevers, Nièvre, Bourgogne, France and died after 1090 in Tonnerre, Yonne, Bourgogne, France.)