Centered in Oughteragh parish, barony of Carrigallen, southern county Leitrim, their territory was bounded by native Irish forests on all sides, Sliabh an Iarainn west and north, Tullyhaw north east, and Conmaiche of Maigh Rein to the south. In the eighth century, when Ua Bruin Breifne claimed large swaths of north Connacht, some Cenel Luachain migrated to Teathbha.