which city am I?:
The city was defended in medieval times by ** Castle, a Norman fortification built on the site of a wooden predecessor. The castle played a key role in the civil wars that followed the death of Henry I. Stephen of Blois reconnoitered ** in 1138 and claimed that the town was impregnable.After Stephen's capture, in 1141, he was imprisoned in the castle. The castle was later taken into royal hands, and Henry III spent lavishly on it, adding a barbican before the main west gate, a gate tower, and a magnificent hall.By the 16th century, the castle had fallen into disuse, but the city authorities had no control over royal property, and so the castle became a refuge for lawbreakers. In 1630, the city purchased the castle; Oliver Cromwell ordered its destruction in 1656.An area outside the castle, known as Old Market, was used as a mustering point for troops. It later became a market for the country people to set up stalls and sell their wares. Old Market was also the site of an autumn fair.The market may have existed as early as the 12th century, and was the site of the first suburb outside the city walls. It had side roads which could accommodate the traffic on market days.
The city had extensive walls built by Geoffrey de Montbray, Bishop of Coutances. These have now largely disappeared, although parts remain on properties in King Street. A gateway in the old wall can now be seen under the tower of the Church of St John the Baptist.