Charles I sent Salebsury a message, personally ordering him to give up Denbigh; after negotiations, Salesbury agreed to surrender on good terms on 26 October. After Salesbury departed, Parliament installed a small garrison in the castle, under the command of Colonel George Twistleton, the new governor. It was used as a prison for political prisoners, including David Pennant, the High Sheriff of Flintshire and there was an abortive Royalist attempt in 1648 to break into the castle to rescue the inmates. In 1659, Sir George Booth led an uprising of Royalist and Presbyterian leaders against the Commonwealth government. A group of Royalist soldiers seized Denbigh Castle in August and took the garrison prisoner. After Booth's defeat at the Battle of Winnington Bridge a few weeks later, the rebels surrendered and the government retook the castle. General George Monck then ordered it to be slighted, put beyond military use. The republican politician John Carter demolished parts of the curtain walls and two towers over the course of six weeks. The site fell further into ruin over the remainder of the century, with its stone being reused to build houses in the town. When granted briefly in 1696 to William Bentinck, the Earl of Portland, complaints were made in Parliament and it reverted to the Crown. 18th – 21st centuries Denbigh Castle remained ruined, although a new grammar school was built in the walled town in 1726 and a bowling green was established around 1769. Castle House, a large private dwelling, was also constructed there in either the second quarter or the middle of the century, using stone taken from the castle ruins and Leicester's church. In the middle of the 19th century, the historian John Williams observed that the walled town remained otherwise deserted, with only three irregular rows of cottages, holding a total of 163 inhabitants; these dwellings attracted complaint from the writer Samuel Lewis, who argued that they "materially diminished the interest excited by the ruins". The western tower of the Burgess Gate was then being used as a private house, as had the eastern tower until a few years before. In the middle of the 19th century, the town created a "Castle Committee" to maintain the ruins; the Crown leased the committee control of the castle and in 1879 lent them £300 to fund repairs to the ruins. The Crown reclaimed control of the Burgess Gate from its