Although not as wealthy as its rival, St John's Abbey, St Botolph's did own considerable holdings in Essex and southern and eastern England. An early source of income was from the tithes of the demesne of Hatfield, granted to the Priory by Henry I from his own personal estates. However, this led later to disputes with Hatfield Regis Priory, until the two settled disputes in 1194. Henry also granted the canons of the priory a third share of the mill called "Midelmeln" (modern Middle Mill in Castle Park, Colchester), as well as confirming the grants made to them by Hugh FitzStephen, under a new condition that they should supply him during expeditions against Wales with a horse worth 5s., a sack and a pike. Other charters confirmed by Henry included the grants made by Count Eustace of Boulogne. Richard I granted a charter on 4 December 1189, in which he extended the list of liberties and confirmed their possessions in detail, these including the churches of Gamlingay in Cambridgeshire, Layer de la Haye and Marks Tey. These and other charters were confirmed by Henry IV in 1400, and again by Henry VI in 1427.