Though deprived of his ally, the Jarl of Orkney, Thorstein failed not to follow up his success, and whilst victory attended the banner of the king of the Dugall in the extreme north, the difficulties of Constantine must have been materially increased by the inroads of Halfdan [Sidenote: A. D. 875.] upon his opposite frontiers, who established himself in Northumbria during the same year, and made incessant incursions upon the neighbouring “Picts” and Britons.[49] A decisive defeat at Dollar, on the borders of Perthshire and Fife, at length forced the Scottish king to submit to the alternative imposed at a later period upon both the English Edmunds, the whole of the northern provinces were made over to the son of Olave, and Constantine purchased a temporary peace at the price of half of his dominions.[50] The success of Thorstein was destined to be ephemeral, the very year of his triumph witnessing the close of his adventurous career. Attacked unexpectedly by the followers of Constantine, he appears to have fallen in an unequal contest; Halfdan was driven from his Northumbrian conquests, perishing soon afterwards in Ireland, and the death of Sigurd’s son Guttorm delivering his father’s earldom once more into the hands of the independent Vikings, the power of the Norsemen was broken up for a time, and the threatening cloud which had loured so darkly over Scotland melted away from the horizon.[51] [Sidenote: A. D. 877.] But the career of Constantine was also approaching its conclusion, and he had little time to profit by the events which had released him from his enemies. As his whole reign had been passed in a continual struggle to protect his country from the Northmen, so it was at length closed with honour on the battle-field in repulsing a hostile landing upon the coast of Fife; though tradition has hinted at a darker tale, that after repelling with success the enemy’s attack he was captured by a party of the retreating Norsemen, and sacrificed by a lingering and cruel death in the gloomy recesses of the Black Cave near Crail.[52] _Aodh (Hugh)_ 877–878. _Eocha_ } { 878–889. _Cyric (Grig)_ } { 878–896. _Donald the Second_ 889–900.