There are two factors that make for the completeness and permanence of conquest—namely, physical superiority and moral superiority. In the art of war and in the apparatus of centralised government, the invaders, we have seen, were superior to the Irish. They could even use the Church as an instrument of the State, and Mr. Orpen boasts that, whereas the Irish bishop of Dublin, Lorcán O'Tuathail, was only a saint, the English bishops who succeeded him were statesmen. Warfare by incastellation, carried on for seventy years, brought three-fourths of the country under control. If to this physical superiority we must add the moral superiority claimed for the Feudal régime by modern admirers—if not by its contemporary champion in letters, Giraldus—there is left only one possible explanation of the failure, the perversity of the Irish mind, afflicted with a double dose of original sin, refusing to recognise either physical superiority in the arts of war or moral superiority in the arts of peace.

Another factor must not be forgotten. The second generation of Feudalism in Ireland was in full possession of all the military resources of the greater part of the country. Just as, in the beginning of the invasion, they had led armies of conquered Flemings and conquered Welshmen, and as a few years later they led a force of conquered Norsemen from Dublin to the battle of Thurles, where they were defeated by Domhnall O'Briain, so in their later wars they led armies of conquered Irishmen for the completion of the conquest. And even conquered Irishmen were not bad fighting material.

Two causes have been assigned by modern writers for the failure of the conquest. One cause alleged is the invasion by Edward Bruce in the years 1315 to 1318. In view of the fact that Bruce's undertaking was itself an ignominious failure, another cause assigned is the transference of the Feudal lordship of Connacht and Ulster from the De Burghs, resident in Ireland, to the Plantagenets, who were absentees. This happened after 1333.

It will be shown that neither of these causes can be held to explain the failure. The conquest was brought to a standstill and the tide was turned more than half a century before the Bruce invasion. The principal factor was national sentiment, intensified and supplied with a more definite political form under a sense of national oppression. Hardly had the sentiment of nationalism acquired this form when a new and unexpected force came to its aid. The value of this new force was crystallised into a proverb by one of the Feudal lords, Sir Robert Savage of the Ards in East Ulster: "Better is a castle of bones than a castle of stones." The policy of conquest by incastellation crumbled away before the castles of bones built up first under the Irish princes of Ulster, afterwards in Connacht, and in time all over Ireland. By a castle of bones, Sir Robert Savage meant a well organised, well armed, and well trained permanent field force. From the days of the Fiana down to the thirteenth century, there had been no such force under the command of an Irish king. Irish law and custom were unfavourable to soldiering as a profession. The new force was not supplied by Irishmen. It came from the Norse kingdom of Argyle and the Hebrides. Already before 1263, when the rulers of this kingdom ceased to be subject to Norway, we find Hebridean leaders helping the Irish of Ulster. Before the close of the thirteenth century, we find organised bodies of Hebridean fighting men on the Irish side, and a common name for them already in use, Gallógláich, a word which was afterwards transplanted into English in the form "galloglasses." It means "foreign soldiers." You may learn from a number of books that the galloglasses were heavy-armed Irish soldiers. They were men of Argyle and the Hebrides who came over to Ireland for military service, or descendants of such men who were settled in Ireland and held on to the profession of soldiers. It may possibly be too much to say that no Irish were admitted to their ranks; but with one very doubtful instance every officer of galloglasses that I find named from the thirteenth century, when they are first heard of, until the seventeenth century, when they are last heard of, bears a Hebridean surname; and the surnames of the majority of their commanders indicate descent from Sumarlidi, who established the kingdom of the Hebrides and Argyle in the twelfth century.

A century or so after the introduction of the galloglasses, we find native Irish troops established in imitation of them. These, however, bear a distinct name, buannadha, "buonies," meaning men on permanent service.

It was this reintroduction of permanent military organisation that ultimately broke down the force of feudal conquest. But as this preceded the Bruce invasion, so also it will be seen that it was itself preceded by a very definite national rally of the free Irish. Let us trace the course of events in greater detail.

In violation of the Treaty of Windsor, the lordship of all Connacht, still unconquered, had been granted to William de Burgh. Marriage with De Lacy's heiress had added the lordship of all Ulster, likewise unconquered, and the Earls of Ulster, chiefs of the great house of De Burgh, thus became titular lords of two-fifths of Ireland. To make their dominion a reality was a great incentive to the completion of the conquest. Half a century after the invasion, the conquest extended to about two-thirds of the country. In Leinster, the mountainous parts southward from Dublin were unsubdued; and in the midlands a group of the old Irish states, side by side, had resisted penetration, under the O'Connors of western Offaly, the O'Mores of Leix, the FitzPatricks of Upper Ossory, and the O'Carrolls of Ely. In Munster, MacCarthy More held out in Muskerry and kept the title of king of Desmond. The kings of Thomond preserved more real power, though part of their territory was occupied by the Norman de Clares. In Connacht, the O'Connor kings were still recognised by the Foreigners, and the kings of Breifne were intact. Along the western seaboard, too, the conquest had not taken effect. The De Burghs were established in the fortress of Galway and in the middle plain of Connacht. In the other parts of Leinster and Munster, and all over the old kingdom of Meath, the Irish states had either been altogether subverted or reduced to subjection.

In Ulster, the Earls of Ulster held effective dominion over so much territory as is now comprised in the counties of Down and Antrim.