The related Ó hAnluain (O'Hanlon) sept were for a couple of centuries chiefs of Oneilland, after which they ruled for several centuries as chiefs of a much reduced Airthir, which by then corresponded to the modern baronies of Orior Lower and Orior Upper, which derive their name from it [REF].
Thus Oneilland became the territory of Art MacBaron O'Neill, son of Matthew O'Neill, 1st Baron Dungannon, with the area in a map from 1560 called "Art Mac Baron his countree" [REF].