Early the next morning Maelmordha left the place, “without permission and without taking leave.” Brian sent a messenger after him to pacify him, but the angry chief, for all reply, “broke all the bones in his head.” He now proceeded to organize a revolt against Brian, and succeeded. Several of the Irish princes flocked to his standard. An encounter took place in Meath, where they slew Malachy’s grandson, Domhnall, who should have been heir if the usual rule of succession had been observed. Malachy marched to the rescue, and defeated the assailants with great slaughter, A.D. 1013. Fierce reprisals now took place on each side. Sanctuary was disregarded, and Malachy called on Brian to assist him. Brian at once complied. After successfully ravaging Ossory he marched to Dublin, where he was joined by Murrough, who had devastated Wicklow, burning, destroying, and carrying off captives, until he reached Cill Maighnenn (Kilmainham). They now blockaded Dublin, where they remained from St. Ciaran’s in harvest (Sept. 9th) until Christmas Day. Brian was then obliged to raise the siege and return home for want of provisions.
The storm was now gathering in earnest, and the most active preparations were made on both sides for a mighty and decisive conflict. The Danes had already obtained possession of England, a country which had always been united in its resistance to their power, a country numerically superior to Ireland: why should they not hope to conquer, with at least equal facility, a people who had so many opposing interests, and who rarely sacrificed these interests to the common good? Still they must have had some fear of the result, if we may judge by the magnitude of their preparations. They despatched ambassadors in all directions to obtain reinforcements. Brodir, the earl, and Amlaibh, son of the King of Lochlann, “the two Earls of Cair, and of all the north of Saxon land,"[220] came at the head of 2,000 men; “and there was not one villain of that 2,000 who had not polished, strong, triple-plated armour of refined iron, or of cooling, uncorroding brass, encasing their sides and bodies from head to foot.”