Brian became _árd-rí_ in 1002, and after that for about twelve years there was peace. Towards the end of that time Gormflaith, who had meanwhile separated from her husband, incited her brother Maelmordha to make war on Brian. Maelmordha and Sihtric began to gather forces for the coming struggle. Sihtric at his mother’s command sought the aid of Sigurthr, Earl of Orkney and of Brodar,[32] a Viking whose fleet then lay off the west coast of Man. Fleets also came from Norway[33] and Iceland to help their kinsmen. The armies under Brian and Maelsechnaill marched towards Dublin, and having encamped near Kilmainham set fire to the district of Fingal (_i.e._, _Fine Gall_, “the Foreigners’ territory”) north of the city. The two armies met at Clontarf on Good Friday morning and the battle, one of the most famous ever fought on Irish soil, raged all that day. The Norsemen suffered a severe defeat, and in attempting to fly for refuge to their ships were slaughtered by Maelsechnaill at Dubhgall’s Bridge, near the Four Courts. Brian himself did not take part in the fight, but he was slain in his tent by Brodar after the battle.[34]
After the Battle of Clontarf the Norsemen became gradually absorbed in the general population except in a few coast towns, where they continued to live more or less distinct and governed by petty kings until the English Invasion (1169). In the chronicles of the twelfth and thirteenth centuries they are generally alluded to as “_Ostmen_” (corruptly _Houstmanni_, _Nosmani_, etc.),[35] and it would seem that when Dublin, Limerick, and Waterford were captured by the English the “Ostmen” had to withdraw to certain districts outside the walls of these towns. Thus, near Dublin, north of the River Liffey, we hear of Ostmaneby[36] (_i.e._, _Austmannabyr_) afterwards called Ostmanstonry, and now known as Oxmanstown. Mention is also made (c. 1200) of a “‘cantred’ of the Ostmen and holy isle,” near Limerick and (c. 1282) of a “vill of the Ostmen”[37] near Waterford.[38] In the records of the fourteenth century, however, there is an almost total absence of references to the “Ostmen” in Ireland.[39]
[1] Zimmer was of the opinion that the Norsemen made their way to Ireland as early as the seventh century. He bases his theory on an entry in the _Annals of Ulster_ and in certain other Irish annals (under the year 617) recording “the devastation of Tory Island by a marine fleet.” (_über die frühesten Berührungen der Iren mit den Nordgermanen_, p. 279 ff. in _Sitzungsberichte der kgl. preussischen Akademie der Wissenschaften_. 1891. Bd. I., pp. 279-317.) But this attack is likely to have been due to Saxon or Pictish raiders rather than to the Norsemen.