Following the Battle of Hastings, William the Conqueror appointed Copsig as Earl of Northumbria, thereby bringing what would become County Durham under Copsig's control. Copsig was, just a few weeks later, killed in Newburn. Having already being previously offended by the appointment of a non-Northumbrian as Bishop of Durham in 1042, the people of the region became increasingly rebellious. In response, in January 1069, William despatched a large Norman army, under the command of Robert de Comines, to Durham City. The army, believed to consist of 700 cavalry (about one-third of the number of Norman knights who had participated in the Battle of Hastings), entered the city, whereupon they were attacked, and defeated, by a Northumbrian assault force. The Northumbrians wiped out the entire Norman army, including Comines, all except for one survivor, who was allowed to take the news of this defeat back.