Brian assembled the forces of the province of Munster and Mael Sechnaill assembled those of Meath, with the intention of laying siege to the Hiberno-Norse city of Dublin, which was ruled by Máel Mórda's ally and cousin, Sigtrygg Silkbeard. Together Máel Mórda and Sigtrygg determined to meet Brian's army in battle rather than risk a siege. Thus, in 999, the opposing armies fought the Battle of Glenmama. The Irish annals all agree that this was a particularly fierce and bloody engagement, although claims that it lasted from morning until midnight, or that the combined Leinster-Dublin force lost 4,000 killed are open to question. In any case, Brian followed up his victory, as he and his brother had in the aftermath of the Battle of Sulcoit thirty-two years before, by capturing and sacking the enemy's city.