Henry now used the bull ‘Laudabiliter’ to sanction an invasion of Ireland. Landing in Waterford in 1171 he rapidly took control of the situation. Strongbow accepted his Lordship of Ireland and was granted the Kingdom of Leinster. Most of the Southern kings followed suit; only O’Connor and the Northern kings resisted. The bishops accepted Henry’s Lordship over Ireland in return for Canterbury being denied jurisdiction over the Irish Church. Leaving in 1172, Henry appointed a justicar or viceroy*, Hugh de Lacy to whom he gave the kingdom of Meath. O’Connor’s resistance stiffened and in 1175 Henry signed a treaty allowing O’Connor to remain king of Connaught as well as high king of those parts of the island that remained in Irish hands. This treaty was largely ignored by the Normans who extended their settlements from the cities of Dublin, Wexford, Waterford, Cork and Limerick as well as establishing new towns and cities such as Drogheda, Galway, Kilkenny and Athlone. At the height of Norman influence in Ireland only Tyrone and Donegal retained a completely Irish identity.

The Norman system of government was as well organised, as was its military machine. For the first time in Ireland, power was centralised, a civil service began to emerge and a parliament was formed consisting initially of the justicar’s council, the major feudal lords, the abbots and the bishops. Later, a lower house was formed consisting of representatives of counties and towns. Taxes were levied and collected and the feudal system of land owning and letting was enforced with the king owning all land and granting it to others in return for their loyalty and certain taxes or services. These lords, in turn, granted parts of their land to minor lords who also had sub-tenants. This meant that the king retained the power to redistribute land as he wished while those at the bottom of society had little prospect of influencing the affairs of the country. Perhaps, partly for this reason, the Church was seen as one of the few ways in which ordinary people could aspire to high office and influence though even here a good deal of patronage was endemic**.

Impressive as the early Norman invasion was, it began to lose its energy and power - the Norman lords feuded among themselves, successive English kings were preoccupied with their adventures in Europe and the Gaelic kings began to reassert themselves. Gaelic culture proved to be remarkably resilient in spite of a number of attempts to suppress it in Norman held lands. In England, the Norman conquest had been a complete success and a united nation emerged which blended Norman and Anglo-Saxon blood in an essentially Norman society. In Ireland, the conquest was never more than partial and, as the centuries passed, the areas under Norman control shrank until only a small area around Dublin, known as The Pale, was left in Norman hands. Within this area, all Irish culture was prohibited and inter-marriage between the Irish and the English (as the Normans may now be styled) was forbidden. Many of the original Norman families, outside the Pale, had adopted Irish customs and ways and had married into the native population. They were no longer colonists but had become part of Irish society, as had the Viking invaders before them. These Norman-Irish or Old English as they came to be called included the influential families of the Fitzgeralds in Kildare and the Butlers in Kilkenny who held sway over large parts of the south of the island. In other areas the Irish kings were virtually independent rulers over their kingdoms, re-establishing the ancient Irish brehon laws*** rather than obeying laws proclaimed from Dublin. For a time it looked as though Ireland was moving towards a form of practical independence from England but enough institutional ties remained for the Tudors to seek to re-impose English rule.

* vice'roy (justicar) - a governor acting in the name of the king or queen.

** endemic – that which is prevalent or regularly found among a people

*** Brehon Law or Brehon Laws - the system of law in use among the Irish until near the middle of the 17th century.