Reginald de Cornhill's father, Gervase, had also been High Sheriff of Kent in 1170-74[citation needed] and his brother Henry de Cornhill[1] sheriff of London.
Cornhill was in charge of collecting the tax of a fifteenth on merchants' imports and exports from 1202 to 1204, when he, along with his fellow keepers William of Wrotham and William of Furnell, accounted for the revenues on the Pipe roll of 1204.
[1] In May 1205 Cornhill, along with Willam of Wrotham, was given custody of one of three dies for the mint at Chichester, but in July the king gave Cornhill's custody to Simon of Wells, the Bishop of Chichester.
[2] Cornhill was constable of Rochester Castle in 1215 on behalf of its then holder Stephen Langton, archbishop of Canterbury.
In 1203 the prior and convent of Prittlewell Priory, in return for a quitclaim of a moiety of the advowson of the church of North Shoebury, granted to Reginald and his heirs the perpetual right to present one clerk to be a monk in their house.