Henry of Saltrey was a Cistercian monk of Sawtry abbey in Huntingdonshire who in the 1180s wrote the Tractatus de Purgatorio Sancti Patricii, the account of the knight Owein’s descent into Saint Patrick’s Purgatory on Lough Derg. Dedicated to Abbot Hugh of Wardon, it became one of the most widespread visions of the otherworld in medieval Europe.