Guillaume married (1) Alfwen. Alfwen died after 1088.
They had the following children:
+ 2 M i William de Cloptunne 3 M ii Simon Pecche 4 M iii Ralph Pecche
Guillaume also married (2) Isilia de Bourges, daughter of Hervey de Bourges and Jenita, after 1088. Isilia died after 1121.
They had the following children:
+ 5 M iv Hamon Pecche 6 F v Basilia Pecche 1 was born after 1088.