The original abbey at Clontuskert was founded near the end of the 8th century by St. Baedan, however nothing from this period remains. The chief patrons of the original abbey were the O’Kelly family as the abbey was situated in their territory.
In the 12th century, an Augustinian Priory dedicated to St. Mary, was founded by Turlough O’Connor, the king of Connacht. However, the friary went through some turbulent times and was burnt to the ground around 1413. The remains which exist today are mostly from the 15th century re-constructed friary.
The remains consist of a church nave and chancel along with remains of a cloister and domestic buildings. Within the ruins there are a number of interesting carvings and some preserved tomb stones.
Some of the history of the 15th century friary includes it being surrendered to King Henry VIII in 1551 and later re-granted to the Prior Donat O’Kellie. It is believed that monks existed in the friary right up to the 17th century.