revision preference src: Deeming her possessions in the east undefendable, she set up headquarters at Hennebont in western Brittany but was driven into Brest and besieged, the siege being broken by the arrival of an English army under the Earl of Northampton at the naval battle of Brest. <SEP> tgt: She deemed her possessions in the east undefendable. She set up headquarters at Hennebont in western Brittany but was driven into Brest and besieged, the siege being broken by the arrival of an English army under the Earl of Northampton at the naval battle of Brest.