 The Uí Méith territory spanned northern County Louth, eastern County Armagh, and later in County Monaghan.John O'Donovan in his notes on the Annals of the Four Masters marks that there were two groups of the Ui Meith name; the Uí Méith Macha (or Uí Méith Tiri) and the Uí Méith Mara.The Uí Méith Macha were based in the barony of Monaghan, County Monaghan.