At the start of 1140, Nigel, the Bishop of Ely, joined Matilda's faction. Hoping to seize East Anglia, he established his base of operations in the Isle of Ely, then surrounded by protective fenland. Nigel faced a rapid response from Stephen, who made a surprise attack on the isle, forcing the Bishop to flee to Gloucester. Robert of Gloucester's men retook some of the territory that Stephen had taken in his 1139 campaign. In an effort to negotiate a truce, Henry of Blois held a peace conference at Bath, at which Matilda was represented by Robert. The conference collapsed after Henry and the clergy insisted that they should set the terms of any peace deal, which Stephen's representatives found unacceptable.