[5] Sligo Abbey, was a Dominican Friary, founded in 1253 by Maurice FitzGerald, 2nd Lord of Offaly,[6] who was Justiciar of Ireland from 1232 to 1245.

[7] His purpose allegedly was to house a community of monks to pray for the soul of Richard Marshal, 3rd Earl of Pembroke,[8] whom he was rumoured to have killed.

[10] At that moment three men competed with each other in the Vatican Standoff: Benedict XIII was pope in Avignon, Gregory XII in Rome, and John XXIII in Pisa.

John replied by sending an apostolic letter from Constance granting indulgences of ten years to all who would visit the church on the feast of the Assumption and the day of Saint Patrick and contribute to its restoration.

The friary was rebuilt in 1416 by Prior Brian, son of Dermot MacDonagh,[11] tanist (prince) of Tirerrill and Collooney.

[13] During Tyrone's Rebellion (1594–1603) the abbey was damaged when Richard Bingham, president of Connaught, besieged Sligo Castle in 1595,[14][15] which was held by Hugh Roe O'Donnell's men.

After the war, at the beginning of the 17th century, the abbey and its lands were granted to Sir William Taaffe in consideration of his services to Queen Elizabeth.

[23] In 1697 when King William reigned alone, the Irish Parliament passed the Banishment Act, which specified that all ordinaries (bishops) and regular clergy (e.g. monks) must leave the country before 1 May 1698.

In 1760 when Father Lawrence Connellan returned from Louvain to Sligo, he found that the buildings had deteriorated so far that it was necessary to find other accommodation.

[31] The abbey ruins consist of the walls of the church, inclusive those of the tower, three sides of the cloister, and remains of the sacristy, the chapter room, the refectory, and the dormitories.

Most of the buildings seem to date from the 13th century, the time of the monastery's foundation and were built in a late romanesque or more specifically Norman Style.

The church's walls are 3 feet 7 inches (1.09 m) thick[32] and their tops are covered with water tables and crowned with ruinous parapets that might once have been crenulated.

This rood screen has been partially reconstructed from its surviving right and left abutments in the abbey's latest restoration (see photo).

The aisle has been entirely demolished and the transept partially, so that the arcade, consisting of three pointed arches supported by octagonal pillars, is exposed.

From this wall protrudes a ruined oriel window giving light to the reader's desk where a friar would read aloud from the scriptures during mealtimes.

[39] The church contains two noteworthy funeral monuments: the "O'Craian altar tomb" and the mural in remembrance of "Sir Donogh O'Connor Sligo".

Its Latin inscription dates it from 1506 and states that it is the tomb of Cormac O'Craian (or Crean) and his wife Johanna, daughter of Ennis (or Magennis).

It shows reliefs of O'Connor and his wife kneeling in prayer in an architectural frame, decorated with heraldic and religious motives.

[41] Sir Donogh O'Connor obtained the letter from Queen Elizabeth that saved the abbey from dissolution, mentioned above.

[42] Sligo Abbey appears in two short stories by William Butler Yeats: The Crucifixion of the Outcast and The Curse of the Fires and of the Shadows.