Cambridge Castle lies in the grounds of Shire Hall on Castle Street, on what is the highest point in Cambridge. The strategic importance of this location overlooking the River Cam was recognised in pre-Roman times and successive Iron Age, Roman and Saxon settlements were established here. In 1068 William the Conqueror gave orders for a castle to be built at Cambridge, and the Domesday Book tells us that 27 houses were demolished to make way for it. The Norman castle consisted of a motte (castle mound) topped by a wooden keep, with a ditched bailey (enclosed courtyard) to the north.
The site is open to the public.
On the N. side of the river, across the bridge and adjoining the county gaol, is a considerable mound of earth, called the Castle Hill, commanding on its summit a wide view of the colleges, and an extensive tract of flat country. Camden says: “Here is a large old castle which seems to have lasted its time.” It was built by the Conqueror on his return from York in 1068, when twenty-seven houses had to be destroyed to furnish a place for it. The mound, though supposed to be of Danish origin, may be an earlier ancient British earthwork, such as are found throughout the land in certain strategical points, and the value of which was recognised by successive rulers, Roman, Saxon, Danish and Norman ; it is likely that during the Danish wars a fortified stockade was erected here.
We know little of the history of the castle. In the time of Stephen it was attacked by Geoffrey de Mandeville, Earl of Essex, who was slain by an arrow during the assault. King John enlarged and repaired the structure, and in 1215 it was taken by the rebellions Barons, but was recovered soon after by the King. John was there in 1216, and on his departure the castle was entrusted to the care of his favourite, Falk de Brent, from whom the Barons again captured it. The Dauphin Louis came to Cambridge to meet these Barons in council after John’s death in 1216. In 1266, during the siege of Kenilworth by the Royal forces, the nobles who had been disinherited and had taken refuge in the inaccessible swamps about Ely, issuing from their strongholds, attacked Cam¬bridge, when King Henry III. came up immediately to the rescue with an army; and he made a ditch round part of the town for its protection, called still the King’s Ditch.
King Edward I., in 1294, lay two nights in this castle. The demolition of the structure appears to have commenced in the reign of Edward III., and early in the fifteenth century the castle was little better than a ruin. Even in the fourteenth century it was chiefly employed as a prison. There was a magnificent hall in it, the stones and timber of which were begged of Henry V. by the Masters and Fellows of King’s Hall towards building their chapel, and other portions of the ruins were employed in building Trinity Chapel. In 1557 some materials from the castle were taken for the mansion of Sir John Huddlestone at Scawston, six miles from Cambridge(This was a grant to him by Queen Mary in return for the destruction of his house by the Cambridge mob after he had given shelter to Mary and her train on their way to Framlingham (q.v.). Hastening away from Scawston in disguise in the morning she beheld her late entertainer’s house in flames, and said, “I will build him a new one.”). Gough says : “Only the keep and gatehouse remain, and two bastions, with part of a third cast up in the Civil War. The gate now standing was built temp. Edward I. or Henry III.” Oliver Cromwell signed a writ to fortify this castle, and added two bastions. The gatehouse, which was a fine structure, was removed so lately as 1842 in order to make room for the building of the county courts. In Fuller’s map, engraved 1634, only the gatehouse is shown, which he says was then employed as a prison ; but in the map of 1574 there are four chief towers beside the gatehouse, and the old keep, a round tower, is shown standing on the summit of the lofty mound known as Castle Hill; this, however, had disappeared in 1634, and the mound stood naked as it is to-day. On the S. side of the gatehouse were some lower buildings, shown in Buck’s view, taken 1731, with a sloping wall and a flight of steps, also given by Grose. But all this is now gone. The masonry of the wall showed several rows of herring-bone work. On the N.W. and N.E. the area of the castle is bounded by Cromwell’s earthworks, within which, formerly the castle yard, is now the county gaol, enclosed in an octagon court. It was designed by John Howard the philanthropist. The wall and ramparts were taken down in 1785.
A wild legend of the twelfth century is preserved by Gervase of Tilbury, being somewhat the same as the story recounted in the “Host’s Tale” in Marmion, canto iii., which is connected with Cambridge Castle. It is the story of a knight named Osbern, who having been told that any warrior who entered alone and at night the camp of Vandlebury, on the Gogmagog Hills, will be encountered by a spectral knight well armed and mounted, determines to prove the reality himself. He accordingly repairs thither with his squire, whom he leaves outside and below, and approaching the camp unattended, is attacked by an unearthly being, armed cap-a-pie, and mounted on a magnificent jet-black charger. Osbern brings him down with his lance, but receives a wound on the thigh from his ghostly opponent. He, however, seizes the bridle of the black steed and leads it away to his squire, who brings the charger into the courtyard of Cambridge Castle, where it is tied securely with strong ropes, and is watched all night by a crowd of people. As morn approaches, the steed becomes rampant and furious, pawing the ground and snorting with fiery rage ; but at cock-crow he bursts his cords, and darting across the court, vanishes! The story also relates how the wound of the knight, being healed, ever bleeds afresh each year on the recurring date of his encounter with the spectral foe. (Castles Of England, Sir James D. Mackenzie, 1896)