advantage of Olaf's absence, Donnchadh, king of Ireland, burnt Dublin. The former, however, was not long delayed by the ruin of his capital, for on 1 Aug. 937 he led an expedition against certain Danes who were sojourning on Lough Rea. These he made prisoners and brought to Dublin, whence the inference (Todd, War of the Gaedhil with the Gaill, p. 281, Rolls Ser.) that the object of this attack was to compel the Danes to take part in the ensuing expedition to England (Four Masters, ii. 633, and Annals of Clonmacnoise, quoted by O'Donovan, ib.; cf. also Ann. Ult. iv. 261). In 937 Olaf fought at the great battle of Brunanburh under the leadership of Olaf Sitricson [q. v.] In the rout of the northern forces he escaped to his ships, and returned to Dublin in 938 (Anglo-Saxon Chron. ii. 88, Rolls Ser.; Ann. Ult. iv. 263; Four Masters, ii. 635). The plunder of Kilcullen in Kildare may more probably be ascribed to Olaf Sitricson, and to a later date; but the year of Olaf Godfreyson's return was again marked by the burning of Dublin and the plunder of the Norse territory by King Donnchadh (ib.) Shortly afterwards (in 939) Olaf apparently left Dublin, and, soon after Æthelstan's death in 940, accepted, jointly with Olaf Sitricson, a vaguely recorded invitation from the Northumbrians to 'Olaf of Ireland' to be their king (A.-S. Chron. ii. 89; Flor. Wig. i. 133, Engl. Hist. Soc.; Will. Malm. i. 157, Rolls Ser.; Rog. Hov. i. 55, Rolls Ser.) With his kinsman he probably shared the kingship until his death in an obscure fight at Tynningham, near Dunbar, in 941 (A.-S. Chron. ii. 89; Sym. Dunelm. Hist. Reg. ii. 94, Rolls Ser.; Rog. Hov. i. 55; Hen. Hunt. p. 162, Rolls Ser.)
Olaf married Alditha, daughter of a certain jarl named Orm (Matt. Westmon. ap. Luard, Flores Historiarum, i. 498, Rolls Ser.)
[In addition to the authorities cited in the text, see Ware's Antiq. Hibern. p. 131; Hodgson's Northumberland, ed. Hinde, i. 148 seq.; Robertson's Early Kings of Scotland, i. 63; Skene's Celtic Scotland, i. 361.]
OLAF Sitricson (d. 981), known in the sagas as Olaf The Red and Olaf Cuaran (i.e. of the Sandal), leader of the Ostmen and king of Dublin and Deira, has been frequently confused with Olaf Godfreyson [q.v.] Like the latter, Olaf Sitricson was of the race of the Hy Ivar, and the great-grandson of Ivar Beinlaus, son of Regnar Lodbrok. His father was the Sitric, king of Deira, who married Æthelstan's sister, and died in 927. The' Egil-saga' (ap. Johnstone, Antiq. Celto Scand. p. 32) is wrong in saying that Olaf was a Scot by his father's, a Dane by his mother's, side; but he probably had Celtic blood; and Florence of Worcester (i. 132, Engl. Hist. Soc.) calls him 'king of many islands.' Upon the death of Sitric, Æthelstan at once annexed Deira, driving out Olaf, who appears to have been too young at this time to resist effectively. His uncle or cousin, however, Godfrey, king of Dublin, immediately left Ireland, and attempted to secure the succession to the Northumbrian throne. He was unsuccessful in obtaining the help of Constantine II of Scotland, who was at that time in alliance with JEthelstan; and, after a vain attempt on York, was driven from the country with Olaf Sitricson.
Probably a few years later Olaf married a daughter of Constantine II of Scotland, and the latter now changed his policv and supported Olaf in his preparation for the impending struggle for the recovery of the Danish kingdom of Deira. This alliance between Constantine and Olaf seems to have been the cause of Æthelstan's raid into Scotland in 934, which probably kept the allies in check for three years.
In 937 the great confederacy of Scots, Britons, and Irish was formed under Olaf Sitricson, Constantine, and Olaf Godfreyson of Dublin. Entering the Humber with a powerful fleet, Olaf Sitricson drove back the lieutenants of Æthelstan in the north, but foolishly permitted himself to be held in check by negotiations while Æthelstan gathered his forces together. William of Malmesbury (Gesta Regum, i. 143) tells the story that Olaf appeared in Æthelstan's camp in the guise of a harper, to which much credit cannot be given: but he seems to have made a night attack on the camp, which failed. The armies finally met on the famous field of Brunanburh, probably in Yorkshire. Æthelstan was completely victorious, and the northmen were driven to their ships. Though it is difficult to distinguish the actions of the two Olafs in the account of the battle given in the poem preserved in the 'Anglo-Saxon Chronicle,' it is clear that neither Olaf Sitricson, as is stated in the 'Egil-saga,' nor Olaf Godfreyson, was among the 'death-doom'd in fight;' and the former probably went back as he had come, by way of the Humber into Scotland.
For the next few years the chroniclers are again confused as to the actions respectively of Olaf Sitricson and Olaf Godfreyson, who had succeeded his father in the kingdom of the Dublin Danes in 934. The latter certainly returned to Ireland after Brunanburh, and it is probable that Olaf Sitricson