 Located close to the southwest border of the ancient Barony of Moycashel, Rosemount was once a stronghold of a prominent branch of the Geoghegan (Mag Eochagain) sept of the Southern UI Neill.Like other Geoghegans in Moycashel, and wider Westmeath, they lost most of their prized grazing land and lake fisheries to the Cromwellian and Williamite settlers (both undertakers and officers) after the Down Survey.Many of the Geoghegan family ancestors are interred in the mortuary chapel at Kill.