Caen was an old city on the north bank of the River Orne. At this time it was larger than any English town other than London. A branch of the River Odon split the town into two parts: the old town and the new town. The old part was a walled city with a very strong castle, but was vulnerable to an English attack at places where the walls had crumbled, in spite of last-minute repairs and improvisations. The new part of the city, the Ile Saint-Jean, was a wealthy district of merchants and landowners who lived on the island formed between the Orne and the Odon. This district was more easily defended, as its perimeter was formed by the rivers and was connected only by three fortified bridges to the neighbouring banks. However, it was often possible, especially in summer, to ford parts of the rivers. The Caen area also featured two large fortified abbeys, one on each side of the city, which could be used to form bastions against an attacking force. Caen was garrisoned by 1,000–1,500 soldiers, a large proportion of whom were professional crossbowmen, and an unknown but large number of armed townsmen. They were commanded by Raoul, the Count of Eu, who was the Grand Constable of France, the senior figure in the French military hierarchy.