Athassel Priory is the largest medieval priory in Ireland, stretching over a 4-acre (1.6 ha) site. The priory dates back to the late 12th century when it was founded by the Augustinians under the patronage of William de Burgh. The priory was burnt twice, once in 1329 by Brian King of Thomond and again in 1581 by John Fitzgerald of Desmond. A large town had grown up around the priory but was destroyed during the two raids. The Priory was finally dissolved in 1537 and the lands given to Thomas Butler, 10th Earl of Ormond who neglected the abbey and it subsequently fell into ruin.