The families of Hugh O'Beirne and Patrick O'Beirne were both descended from Teige O'Beirne resident in the Drumsna area in the early 18th century. These two branches of the O'Beirne family were living at Jamestown and Dangan (the original O'Beirne stronghold) in the early 19th century. Patrick O'Beirne was a son of Colonel Andrew O'Beirne, Chief of the O'Beirne clan in the late 18th century. Andrew lost most of his property after the 1798 rebellion and four of his sons emigrated from Ireland. Patrick remained at Dangan and O'Beirnes continued to live there until at least the late 1830s.
Dangan Castle was one of the main residences of the O'Beirne clan but was badly decayed by the early 17th century. Dangan House was built nearby and was occupied by the O'Beirne family from the 17th to the 19th centuries. They held Dangan from the King family. Father Martin Coen writes that Dangan House in the parish of Kilmore was the birthplace of George J. P. Browne, Bishop of Galway in the 1830s. Patrick O'Beirne was the occupant in 1814 and 1837. It was the residence of Mathew Hanly at the time of Griffith's Valuation when the house was valued at £8. Farm buildings exist at the site.