High Quality Content by WIKIPEDIA articles! The Great Siegeof Scarborough Castle was a major conflict for control of one of England`s most important stone fortresses during the English Civil War (1642–1651), fought between Oliver Cromwell`s parliamentary Roundheads and the Royalists loyal to King Charles I (reigned 1625–1649). In February 1645, Parliamentary forces laid siege to the castle for five months of bombardment and bloody fighting, destroying most of the keep, before the defenders finally surrendered. This was a significant though short-lived victory in Oliver Cromwell`s bid to replace the monarchy with his own republican regime, one which led to a second, far less bloody and destructive siege later in the year when the new garrison switched sides. The castle finally came under Parliamentary control in December 1645, and remained so until the restoration of the monarchy.