Approximately 150 meters west of the college and friary church, hidden by trees, lay the steeply inclined remains of a twelfth-century Norman motte and bailey, built by Richard Fleming in the 1170s. This was the seat of the Flemings of Slane, barons of Slane. The Flemings moved to a castle on the left bank of the River Boyne, the current location of Slane Castle. The Flemings were lords of Slane from the twelfth century until seventeenth century, when the Conyngham family replaced them as lords of Slane during the Williamite Confiscations.