Parliamentary forces successfully besieged Oxford in 1646 and the city was occupied by Colonel Ingoldsby.[45] Ingoldsby improved the fortification of the castle rather than the surrounding town, and in 1649 demolished most of the medieval stonework, replacing it with more modern earth bulwarks and reinforcing the keep with earth works to form a probable gun-platform.[46] In 1652, in the third English Civil War, the Parliamentary garrison responded to the proximity of Charles II's forces by pulling down these defences as well and retreating to New College instead, causing great damage to the college in the process.[45] In the event, Oxford saw no fresh fighting; early in the 18th century, however, the keep was demolished and the top of the motte landscaped to its current form.[3]