Royalists invaded Parliamentary-controlled Dorset in 1643, taking Portland and Sandsfoot. The flow of the war turned against the King, and the Dorset forts were besieged in 1644 and 1645, with Sandsfoot falling to Parliament. By March 1646, Thomas Fairfax had entered Cornwall with a substantial army. The captain of the castle was invited to retreat to the stronger fortress of Pendennis, but he surrendered immediately without putting up resistance. Pendennis was bombarded from the land and blockaded by a flotilla of ships. The captain, Sir John Arundell, agreed to an honourable surrender on 15 August, and around 900 survivors left the fort, some terminally ill from malnutrition. Pendennis was the penultimate Royalist fortification to hold out in the war, followed by Portland Castle which finally surrendered in April 1646. Second English Civil War After a few years of unsteady peace, in 1648 the Second English Civil War broke out, this time with Charles' Royalist supporters joined by Scottish forces. The Parliamentary navy was based in the Downs, protected by the nearby Henrician castles, but by May a Royalist insurrection was underway across Kent. Sandown Castle declared for the King, and the soldier and former naval captain Major Keme then convinced the garrisons at Deal and Walmer to surrender. Sandgate Castle probably joined the Royalists as well. With both the coastal fortresses and the navy now under Royalist control, Parliament feared that foreign forces might be landed along the coast, or military aid sent to the Scots. Essex also rose in rebellion in June and the town of Colchester was taken by the Royalists. Sir Thomas Fairfax placed it under siege, and Mersea Fort was taken by Parliamentary forces and used to cut off any assistance reaching the town by river. Meanwhile, Parliament defeated the Kentish insurgency at the Battle of Maidstone at the start of June and then sent a force under the command of Colonel Rich to deal with the castles of the Downs. Walmer Castle was the first to be besieged and surrendered on 12 July. An earthwork fort was then built between Sandown and Deal, who each may have been defended by around 150 men each. Deal, which had been resupplied by the Royalists from the sea, was besieged in July. A Royalist fleet bombarded the Parliamentary positions and temporarily landed a force 1,500 Flemish mercenaries in support of the revolt, but a shortage of money forced