Henceforward throughout the rather more than a century and a half which intervened between the battle of Clontarf and the Norman invasion, Ireland remained a helpless waterlogged vessel, with an unruly crew, without rudder or compass, above all, without a captain. The house of O'Brien again pushed its way to the front, but none of Brian's descendants who survived the day of Clontarf seem to have shown a trace even of his capacity. A fierce feud broke out shortly after between Donchad, his son, and Turlough, one of his grandsons, and each successively caught at the helm, but neither succeeding in obtaining the sovereignty of the entire island. After the last-named followed Murhertach also of the Dalcassian house, at whose death the rule once more swung round to the house of Hy-Nial and Donald O'Lochlin reigned nominally until his death in 1121. Next the O'Connors, of Connaught, took a turn at the sovereignty, and seized possession of Cashel which since its capture by Brian Boroimhe had been the exclusive appanage of the Dalcassians. Another O'Lochlin, of the house of O'Neill, then appears prominently in the fray, and by 1156, seems to have succeeded in seizing the over-lordship of the island, and so the tale goes on--a wearisome one, unrelieved by even a transitory gleam of order or prosperity. At last it becomes almost a relief when we reach the name of Roderick O'Connor, and know that before his death fresh actors will have entered upon the scene, and that the confused and baffling history of Ireland will, at all events, have entered upon a perfectly new stage. [Illustration: ROUND TOWER AT DEVENISH.] X. THE ANGLO-NORMAN INVASION. The invasion of Ireland by the Anglo-Normans differs in several respects from other invasions and conquests, not the least singular feature about it being that nearly the whole of that famous band of knightly adventurers who took part in it, and to whose audacity it was in the first instance due, were more or less closely related to one another, either as brothers, nephews, uncles, or cousins. The connecting link between these variously-named relations was one Nesta, princess of South Wales, daughter of a Welsh king, Rice ap Tudor, a heroine whose adventures are of a sufficiently striking, not to say startling, character. By dint of a succession of alliances, some regular, others highly irregular, she became the ancestress of nearly all the great Anglo-Norman families in Ireland. Of these the Fitzgeralds, Carews, Barrys, and Cogans, are descended from her first husband, Gerald of Windsor. Robert FitzStephen, who plays, as will presently be seen, a prominent part in the conquest, was the son of her second husband, Stephen, the Castlelan of Abertivy, while Robert and Meiler FitzHenry, of whom we shall also hear, are said to have been the sons of no less a person than King Henry I. of England. [Illustration: WEST FRONT OF ST. CRONAN'S CHURCH, ROSCREA. (_From a Photograph_.)]