Gwilym was born about 1242, the son of unknown parents. The place is not known.
His wife was Catrin verch Elidir. They were married, but the date and place have not been found. Their only known child was Gruffydd Goch ap Gwilym (?-?).
| Event | Date | Details | Source | Multimedia | Notes |
|---|---|---|---|---|---|
| Birth | ABT 1242 |
|