 Complete the following phrase:  The fighting in north-east France was indecisive during January and the first week of February. During the Battle of Brienne 29 January 1814 Napoleon surprised Blücher at his headquarters and nearly captured him. Having learnt that Napoleon was at hand Blücher fell back a few miles to the east the next morning to a strong position covering the exits from the Bar-sur-Aube defile. There he was joined by the Austrian advance guard and together they decided to accept battleindeed they had no alternative, as the roads in rear were so choked with traffic that retreat was out of the question. At about noon on 2 February Napoleon attacked them opening the 