In Pender's Census of 1659, Nicholas Mahon Esq. was recorded as the owner of Elphin.
In February 1666 Captain Nicholas Mahon was granted over 2,700 acres in the barony of Roscommon and in July 1678 he was granted over 3,000 acres in the baronies of Roscommon and Ballintober county Roscommon. The latter became the Manor of Ballynamully or Strokestown, 500 acres to be held as demesne.
Thomas Mahon represented the borough of Roscommon 1739-1763 and the county from 1763-1782.