Sir Henry Dillon
From A Compendium of Irish Biography, 1878
Dillon, Sir Henry. The Dillon or Delion family are said by Lodge to be descended from an Irish monarch of the 6th century. An ancestor of the family was obliged toflee to France, on account of some misdeed, and settled there. The subject of this notice came to Ireland in 1185 as secretary to Prince John, and was granted large territories belonging to the MacCarrons, MacGeoghegans, and O'Melaghlins, comprising the present County of Longford and the adjacent country. This territory was called Dillon's Country until reduced into shire ground by Henry VIII., when it was divided into the Barony of Kilkenny West, and others. Sir Henry built a mansion house and church at Drumraney, and abbeys at Athlone, Holy Island, Hare Island, and elsewhere. He was buried in the abbey of Athlone. He married a daughter of John de Courcy, Earl of Ulster. His descendants were ennobled in 1619 in the person of Sir James Dillon, created Lord Dillon, Baron of Kilkenny West, advanced in 1622 to the dignity of Earl of Roscommon.
216. Lodge's Peerage of Ireland, Revised and Enlarged by Mervyn Archdall. 7 vols. Dublin, 1789.