ARMAGH Ard Mhacha.
County in Northern Ireland, south of Lough Neagh. Its southern and western borders are with the Republic. In the early middle ages it was part of Airgialla, but by 850 the district around the monastery of Armagh, said to be St Patrick’s foundation, had been placed under the protection of the Northern Uí Néill, though that did not prevent the Kings of Airgialla, or later the Vikings, from raiding the region.
In the twelfth century, when Ireland was being ecclesiastically reorganised into dioceses, the town of Armagh became the see of an Archbishop, soon recognised as the Primate of Ireland. Armagh still remains the seat of the Primates of the Roman Catholic Church in Ireland and of the (Anglican) Church of Ireland.
The future county was usually outside the area of Norman and English domination, the north being in the Uí Néill territory of Tir Eoghan, the south in Irish Uriel, an area where English influence fluctuated. The county was created in 1585, but the times were troubled in Ulster, and it was not firmly established until the Plantation of Ulster in the reign of James I.
As a result of the Plantation, Co. Armagh became more than 50% Protestant in population, though the south remained strongly Catholic. In 1920 it became one of the Six Counties that formed Northern Ireland.
In 1974 the county, though it remained in ceremonial existence, ceased to be an administrative body, and its powers passed to three districts. Armagh was formed entirely from the county, while both Craigavon and Newry & Mourne were made up from parts of Co. Down as well. The district of Newry & Mourne, in the south, was strongly Catholic and firmly Republican.