(1190–1231), justiciar of Ireland 1224–6. His father William Marshal I gave him as a hostage to King John after doing homage to King Philip of France for his Norman lands in 1205. He opposed John and his father during the civil war, and was excommunicated. He supported the invasion of England by Louis, son of Philip, and captured Worcester before changing sides. In 1220 and 1222 his Welsh lands were ravaged by Llywelyn ap Iorwerth of Gwynedd. In 1224, as justiciar, he subdued Hugh de Lacy's rebellion in Ireland. He was removed in 1226 for opposing the treatment of Aodh O'Connor (Áed Ó Conchobair) in the run-up to the conquest of Connacht. He founded the Dominican priory of the Holy Trinity in Kilkenny in about 1225 and began construction of the castles of Carlow and Ferns. He died in April 1231. His second wife Eleanor was Henry III's sister.
From The Oxford Companion to Irish History in Oxford Reference.
Subjects: European History.