Following the Nine Years' War and just before the process of
colonising Ulster with loyal Protestant subjects, the arrangement of dividing mighty Gaelic lordships into smaller weaker lordships, such as what happened in
County Monaghan with the MacMahon's, occurred with Iveagh. In 1605 the "Commission for the Division and Bounding of the Lords" was established to replicate the Monaghan arrangement, with Art Roe Magennis applying to be made Lord Iveagh. In February 1607, the commission however decided to break up Iveagh, a process that continued until 1610, seeing the creation of fifteen freeholds. The Magennises were granted thirteen of these freeholds, with Art Roe being granted the largest. The rest however was given to officers in the Crown forces, most of whom had served in the Nine Years' War under Sir Henry Bagenal and
Sir Arthur Chichester. Amongst the freehold grants to the Magennises were: • Ever MacPhelimy Magennis of Castlewellan, who was granted eleven townlands, constituting the Castlewellan estate in the parishes of Kilmegan and Drumgooland. • Brian MacHugh MacAgholy Magennis of Muntereddy, who was granted seven and a half townlands, constituting the Bryansford estate in the parishes of Maghera (Bryansford) and Kilcoo. This estate was held by the
Earl of Roden on account of his descent from Brian. Sir Arthur Magennus, stated as being chief of the Magennises in 1610, granted from his own large estate to his kin: • Glassney Roe Magennis of Ballymoney, three townlands. • Fer-doragh MacFellimey MacPrior Magennis of Clanvarraghan, three townlands in Kilmegan parish. The lands the Magennises held in these Iveagh freeholds diminished as the officers and other speculators went about extending their possessions at their expense through legal and illegal means. The failure of the native Irish to properly understand the English legal system resulted in them accruing large debts resulting in them having to sell vast swathes of their lands or losing them as collateral when they failed to pay their debts. Despite finally being appointed Lord Iveagh in 1623, Art Roe Magennis also found himself in a dangerous financial position ==Viscount Magennis of Iveagh==