But none of these things happened.

England, whose political and social development had been hastened by the Norman Conquest, desired to extend her influence to Ireland.

'She wished,' as Froude strangely tells us, 'to complete the work of civilisation happily begun by the Danes.' But in actual fact she only succeeded in trammelling the development of Irish society, and maintaining in the country an appalling condition of decadent stagnation, as the result of three centuries and a half of intermittent invasions, never followed by conquest." On the other hand the triumph of Irish culture was easy and absolute.
Ireland, unvisited by the legions and the law of Rome, had evolved a different vision of the life of men in community, or, in other words, a different idea of the State.

Put very briefly the difference lay in this.

The Romans and their inheritors organised for purposes of war and order, the Irish for purposes of culture.