Cambridge from castle Mount - G F Sargent mid 19th century
History of Cambridge Castle
View from Castle Hill
The motte remains of the castle built by William the Conqueror in 1068 to control the river crossing. It lay within the stone walls of the Roman town. In the process 27 houses were demolished. A stone bailey was rebuilt in stone by Edward in 1294. It seems to nave been surrounded by wet moats.
Cambridge Castle historical map
By 1367 the castle was already in a defective state although even in 1585 attempts were made to retain the curtain wall. By 1606 the S.W. gatehouse was the only complete building left because of its use as a prison.
In 1643, because of Cambridge being the headquarters of the Eastern Counties Association, the Bailey works were reconstructed as a bastioned trace fort. In 1647 the new defences were slighted but three bastions remained.
Between 1802 and 1847 a new octagonal County gaol designed by G Byfield was built. In 1842 the SW gatehouse was pulled down to make way for the Court House, itself demolished in 1954. In 1932 the new Shire Hall was built on the site freed by the demolition of the County gaol.
Documents about the castle’s role as a prison can be found here:
Cambridge County Gaol and House of Correction
Cambridge Castle 19th cent.
There is a Wikipedia entry.
The following map from 1895 shows the probable line of the Roma wall and ditch.
Cambridge Castle 1895 suggested plan