Guillaume was the son of unknown parents. The date and place of his birth have not been found.
He died after 1313. The place is not known.
His wife was Marie de Villeray. They were married, but the date and place have not been found. Their only known child was Geoffroy IV (?-1371).
| Event | Date | Details | Source | Multimedia | Notes |
|---|---|---|---|---|---|
| Death | AFT 1313 |
|
| Attribute | Date | Description | Details | Source | Multimedia | Notes |
|---|---|---|---|---|---|---|
| Nobility Title | seigneur d'Illiers |