The domestic dissensions of the men of Erinn, ruinous as they were to the nation, gave it at least the advantage of having a brave and resolute body of men always in arms, and ready to face the foe at a moment's notice, when no selfish policy interfered.

In 937 Athelstane gained his famous victory over the Danes at Brunanbriegh in Northumberland, and came triumphantly to reclaim the dagger[208] which he had left at the shrine of St.John of Beverley.
After his death, in 941, Amlaff returned to Northumberland, and once more restored the Danish sway.

From this time, until the accession of the Danish King Canute, England was more or less under the dominion of these ruthless tyrants.[209] "The Danes of Ireland, at this period, were ruled by Sitric, son of Turgesius, whose name was sufficient to inspire the Irish with terror.
Through policy he professed willingness to enter into a treaty of peace with Callaghan, King of Munster; and, as proof of his sincerity, offered him his sister, the Princess Royal of Denmark, in marriage.

The Irish king had fallen in love with this amiable and beautiful princess, and he readily consented to the fair and liberal measures proposed.

He sent word to Sitric he would visit him; and, attended by a royal retinue, to be followed in a little time by his guards, as escort for his future queen, proceeded to meet his royal bride.
"Sitric's project of inveigling the King of Munster into his district, in order to make him prisoner, under the expectation of being married to the Princess of Denmark, having been disclosed to his wife, who was of Irish birth, she determined to warn the intended victim of the meditated treachery, and accordingly she disguised herself, and placed herself in a pass which Callaghan should traverse, and met him.