Ross Errilly was founded by the Franciscan order of monks in the fifteenth century. Ross Errilly had many supporters the most prominent of all were the De Burgho family later known as the Burke family after their name became anglicised.
The life of the monks changed drastically after the English Reformation in 1534. Following the reformation English authorities made attempts to arrest the monks of Ross Errilly. In 1538 the English authorities arrested over 200 monks. The monks were continually expelled throughout the late fourteenth and early fifteenth century. In 1604 Ulick Burke continued his family tradition of supporting the monks of Ross Errilly. Which allowed the monks to reoccupy Ross Errilly following English raids.
In 1656 English forces once again attacked Ross Errilly but the monks had been given notice and evacuated hours earlier. By 1712 the monks had returned to Ross Errilly but abandoned the friary in 1731 for reasons unknown. In 1753 the land Ross Errilly was owned by Lord St. George, a local noble. He allowed the monks to return to the friary. This was a dangerous time to be supporting catholic's due to the Penal Laws. Lord St. George risked prison to help the monks. Peace did not last at Ross Errilly as the authorities were alerted that Lord St. George was harbouring catholic’s. Lord St. George was alerted to this and had Ross Errillies monks evacuated before transforming the site into a factory. He did this by employing local weavers, white washing the walls and installing looms. St. Georges deception worked and the authorities inquiry was ended. The monks continued to live close to the abbey on an island in the Black River and would celebrate Sunday mass in the deteriorating friary for 36 years. Ross Errilly descended into ruin following its abandonment. A man called Oliver Burke made repairs to the friary including repairs to the tower and removing obstructions. Oliver Burkes influence is still felt today as Ross Errilly Friary is now maintained by “The Office of Public Works”. Ross Errilly friary is now famous for being one of Ireland’s oldest friaries and is open to the public.