See also
| Husband: | Gilbert * + of CLARE (1180-1230) | |
| Wife: | Isabel * + MARSHALL (1200-1240) | |
| Children: | Agnes of CLARE (1218- ) | |
| Amica of CLARE (1220- ) | ||
| Richard * of CLARE (1222-1262) | ||
| Isabel of CLARE (1226- ) | ||
| William of CLARE (1228- ) | ||
| Gilbert of CLARE (1229- ) | ||
| Marriage | 9 Oct 1217 | England |
| Name: | Gilbert * + of CLARE | |
| Sex: | Male | |
| Father: | Richard * + of CLARE (1162-1218) | |
| Mother: | Amice * + FITZWILLIAM (1160-1224) | |
| Birth | 1180 | Hertford, Hertfordshire, England |
| Occupation | Earl of Gloucester | |
| Title | Earl of Gloucester | |
| Death | 25 Oct 1230 (age 49-50) | Penrose, Brittany, France |
| Name: | Isabel * + MARSHALL | |
| Sex: | Female | |
| Father: | William + MARSHAL (1146-1219) | |
| Mother: | Isabel + of CLARE (1166-1220) | |
| Birth | 9 Oct 1200 | Pembrokeshire, Wales |
| Death | 16 Jan 1240 (age 39) | Berhamstead, Hertfordshire, England |
| Name: | Agnes of CLARE | |
| Sex: | Female | |
| Birth | 1218 | |
| Name: | Amica of CLARE | |
| Sex: | Female | |
| Birth | 1220 | |
| Name: | Richard * of CLARE | |
| Sex: | Male | |
| Spouse: | Maud * + of LACY (1223-1288) | |
| Birth | 4 Aug 1222 | Mellent, Gloucestershire, England |
| Occupation | Earl of Hertford, Gloucester, Clare | |
| Title | Earl of Hertford (5th) | |
| Title | Earl of Gloucester (6th) | |
| Title | Earl of Clare (8th) | |
| Death | 15 Jul 1262 (age 39) | Ashenfield Manor, Waltham, Kent, England |
| Burial | 28 Jul 1262 | Canon's Church in Tonbridge |
| Name: | Isabel of CLARE | |
| Sex: | Female | |
| Birth | 1226 | |
| Name: | William of CLARE | |
| Sex: | Male | |
| Birth | 1228 | |
| Name: | Gilbert of CLARE | |
| Sex: | Male | |
| Birth | 1229 | |
Gilbert de Clare, 4th Earl of Hertford, 5th Earl of Gloucester (1180 – 25 October 1230) was the son of Richard de Clare, 3rd Earl of Hertford, from whom he inherited the Clare estates. He also inherited from his mother, Amice Fitz William, the estates of Gloucester and the honour of St. Hilary, and from Rohese, an ancestor, the moiety of the Giffard estates. In June 1202, he was entrusted with the lands of Harfleur and Montrevillers.
In 1215 Gilbert and his father were two of the barons made Magna Carta sureties and championed Louis "le Dauphin" of France in the First Barons' War, fighting at Lincoln under the baronial banner. He was taken prisoner in 1217 by William Marshal, whose daughter Isabel he later married on 9 October, her 17th birthday.
In 1223 he accompanied his brother-in-law, Earl Marshal, in an expedition into Wales. In 1225 he was present at the confirmation of the Magna Carta by Henry III. In 1228 he led an army against the Welsh, capturing Morgan Gam, who was released the next year. He then joined in an expedition to Brittany, but died on his way back to Penrose in that duchy. His body was conveyed home by way of Plymouth and Cranborne to Tewkesbury. His widow Isabel later married Richard Plantagenet, Earl of Cornwall & King of the Romans. His own arms were: Or, three chevronels gules.
Hertford had six children by his wife Isabel, née Marshal:[1]
Agnes de Clare (b. 1218)
Amice de Clare (1220–1287), who married the 6th Earl of Devon
Richard de Clare (1222–1262)
Isabel de Clare (1226–1264), who married the 5th Lord of Annandale
William de Clare (1228–1258)
Gilbert de Clare (b. 1229)