John Mansel

John Mansel was a son of a cleric who rose to be one of Henry III's (r. 1216-1272) key servants, serving him as administrator, diplomat, and soldier. He was educated at court and began his career with a post in the Exchequer in 1234 and for the next thirty years until his death in 1265, he held a number of key posts. He held the great seal 1246–7 and 1248–9.

Mansel served as a soldier when Henry III dispatched a force under Henry de Trubleville in 1238 to aid the Emperor Frederick II (r. 1220-1250) in his warfare with the cities of northern Italy. He distinguished hiself in military operations and continued to serve as a soldier in Henry’s military operations in France. Mansel ended his military career after a stone crushed his leg in France in 1243.

At his height Mansel was worth £15,000, about 0.45% of net national income, or £4.9bn in 2010’s terms.