Gilbert de Clare, 5th Earl of Gloucester, 5th Earl of Hertford, was born 1180 to Richard de Clare, 4th Earl of Hertford (c1153-1218) and Amice FitzRobert, Countess of Gloucester (c1160-1220) and died 25 October 1230 of unspecified causes. He married Isabel Marshal (1200-1240) 9 October 1217 JL .
Children
| Name | Birth | Death | Joined with |
| Agnes de Clare (1218-) | |||
| Amice de Clare (1220-1287) | |||
| Richard de Clare, 6th Earl of Hertford (1222-1262) | 4 August 1222 | 15 July 1262 | Megotta de Burgh Maud de Lacy, Countess of Lincoln (1223-c1287) |
| Isabel de Clare (1226-1264) | 2 November 1226 | 10 July 1264 | Robert de Brus (c1210-1295) |
| William de Clare (1228-1258) | |||
| Gilbert de Clare (1229-) | |||
Footnotes (including sources)
| ‡ General |