Then the battle proper got under way. It is described in the "Cogad" as remarkably loud and bloody. The men of Connacht fought the men of Dublin, and the fighting was so fierce that only 100 Connachtmen and twenty Dublinmen survived. The last casualties occurred at "Dubgall's Bridge", which Seán Duffy suggests was a bridge over the River Tolka, on the road back to Dublin. Brian's son Murchad, at the head of the Dál gCais army, took on the foreign Vikings and, according to the "Cogad", he himself killed 100 of the enemy—fifty with the sword in his right hand and fifty with the sword in his left. The Vikings wore mail; the Irish did not. Yet the Irish gained the advantage, partly through the use of small spears, which they hurled at the enemy, and partly through numerical superiority.