The Cistercian Abbey at Abbeyshrule, County Longford, Ireland, was founded in 1200 by the O’Ferralls, the Irish chieftains of the district and it was part of the Mellifont family - although after Stephen of Lexington's visitation in 1228 it became as daughter house of Bective.

The abbey was situated on the side of the River Inny, four and a half miles east north-east of Ballymahon, on the borders of Longford and Westmeath. The official Latin name was derived from the location of the abbey: ‘Flumen Dei’, the river of the god. By the later Middles Ages the abbey was completely under the control of the Ferrall family. When Abbot Gilbert died in 1430 Kenan O’Ferrall unlawfully took possession of the abbey and was to be removed. However, Kenan was still abbot in 1455 when he was accused of misrule by a monk of St. Anastasius.

There are no surviving sources concerning the revenue of the abbey, but it is reasonable to assume that Abbeyshrule was never prosperous. In 1476 it was recorded that the abbey had been burnt by English forces, although we do not know the extent of the damage. In 1540-1 it was reported that ‘long before the dissolution’ the goods and of the monastery had been carried off and consumed by the O’Ferralls. It is thought that, even if monastic life had survived until 1540, it is unlikely that it continued beyond this date. In 1569 the site and possessions were granted to Robert Dillon and the abbey was officially suppressed by Queen Elizabeth in 1592. The abbey church survives relatively intact but all the other monastic buildings have vanished. From Google Earth it is possible to outlines of what might have been the monastic buildings as well as medieval ploughing. The church, parts of which date back to the 13th century, is now covered in vegetation although a local group does plan to renovate the tower.

The remaining structure shows evidence of three distinct phases of construction. Initially an aisle-less church was built, the east and north walls still partially exists, and the remains of a cloister arcade can be found as well as part of the crossing tower. During the 15th century the church was enhanced; the crossing tower's arch was blocked and three barrel vaulted chapels were added to the tower's western end and a door in the tower's southern wall led into what had been the cloister. The discovery of bones and skulls outside the east wall of the church has led to unsupported tales of the monks being slaughtered. During the 17th century, or possible slightly later, the presbytery was converted into a small parish church. The abbey church, as is common in Ireland, was and is used as a Catholic graveyard.

The only other ruins are of a post-Reformation tower house which stands approximately 100 feet to the south of the church and which is totally invisible under a layer of dense ivy. It originally had four floors which were accessed by a spiral staircase. It was probably built after the dissolution in the late 16th century.

Plan of the abbey church: