High Quality Content by WIKIPEDIA articles! Mount Grace Priory, in the parish of East Harlsey, North Yorkshire, England is today the best preserved and most accessible of the ten medieval Carthusian houses (charterhouses) in England. Set in woodlands, it was founded in 1398 by Thomas Holland, 1st Duke of Surrey, the son of King Richard II`s half-brother Thomas, earl of Kent, it was the last monastery established in Yorkshire, and one of the few founded anywhere in Britain in the period between the Black Death (1349–50) and the Reformation. It was a fairly small establishment, with space for a prior and twenty-three monks.