The history of the castle begins in the Norman period. It can be hypothesised that the place was inhabited in the Late Iron Age and in the Roman times, but archaeologically, this has not yet been proven. In 1068 William I ordered the construction of a castle in Cambridge. It was built as a motte-and-bailey type from which the Cambridge Castle is the oldest one. According to the Domesday Book 27 houses were demolished in order to make way for the castle.
In the 13th century, Edward I ordered the rebuilding of the castle and, as a result, the bailey was reconstructed in a rectangular form. The castle was skirted by wet moats, and they could separate also the bailey from the motte. From this period a curtain wall, a southwestern gatehouse with barbican opposite the moat, and a southern, a western and northern tower are known to have existed. A great hall was built in the bailey, and a chapel is also mentioned during the Edwardian period.
During the Middle Ages, the buildings has already begun to deteriorate. Reclaimed stones from the site were used for building colleges and houses in Cambridge.

By 1606, only the gatehouse was preserved completely, because it was used as a prison. At the outbreak of the Civil War, the important status of Cambridge required the defensive properties of the castle to be improved. Between 1642 and 1643 the castle was fortified, following the line of the former curtain wall. On the place of the former towers, bastions were constructed and brick barracks were built on the location of the great hall.

Between 1802 and 1807, a new octagonal County Gaol was built. The last traces of the ditch surrounding the motte were filled up with building debris. In 1842, the last medieval building - the gatehouse - was destroyed during the construction of the Court House, which survived until 1956.
In 1932 a new Shire Hall replaced the County Gaol.