Mobarnan was the seat of the Jacob family in the 18th and 19th centuries. Occupied by Samuel Jacob in 1814, M. Jacob in 1837 and by Samuel Jacob at the time of Griffith's Valuation. He held the property in fee and the buildings were valued at £37+. Later the home of the Tennant family. This house was enlarged in the early 19th century and is still in use as a residence. In the 1970s it was owned by Major Marcus William Keane, formerly of Beech Park, and his wife, Anne R. Armitage of Noan, Co Tipperary.