The county was originally Uriel/Oriel, as it formed part of the ancient Irish territory of Oirghialla. It was later changed to Louth and takes its name from Louth village, once the cathedral city of the Bishop of Clogher. The name therefore derives, like the village, from the chief Celtic deity Lugh, as do many cities and regions on the continent (e.g. Lyon, Lugano, Leiden). Louth was one of the first round of counties founded, on conquered Gaelic territory, by the Anglo-Norman invaders of the late twelfth century. The failure of the Anglo-Normans to complete their conquest, especially of the north and west of Ireland, inclduing most of Oirghialla, left Louth small and precarious, exposed to the depredations of the Gaelic Irish, while it also acted as a garrison and as a stepping-off point for English incursions further into Ulster (of which Louth was then a part). The Anglo-Normans established eleven ?Boroughs? across the county, several of them later becoming major, walled towns and thriving to this day. Ardee, Carlingford and Drogheda - which was two separate towns, in two different counties, until 1412 - and Dundalk are examples of such, while other Anglo-Norman boroughs are now long abandoned and almost entirely forgotten (for example Castlering and Castle Roche).
Louth was fairly thoroughly colonised, and remained, by and large, loyal to the English crown throughout the mediaeval period. On Mayday 1316, Edward de Bruce, less-famous brother of the Scottish king, Robert, crowned himself King of Ireland, in Dundalk. Just over two years later, in October 1318, he was killed by the English at Faughart Hill, nearby. In the later Middle Ages the English power in Ireland retreated further, resulting in the physical delineation of the area that remained under English government control by the erection of a bank, topped by a fence of sharpened stakes (a paling). Most of Louth lay within this retrenched colony, still referred to as ?the Pale?.
