post and he carried out an extensive redevelopment of the castle. Worsley filled in half of the castle's courtyard to produce a solid artillery platform able to hold eight heavy guns with an uninterrupted field of fire over the sea, and he probably also constructed the Master Gunner's House on the other side of the castle. Nonetheless, an inspection in 1586 showed that the fortification was in poor condition. Work costing £50 was done in 1587, including the erection of an earth bulwark alongside the castle to mount additional guns. The next year saw the attempted invasion of England by the Spanish Armada, after which further repairs were carried out on the castle. By 1599 the Crown was informed that the castle, which was still considered an important defence for the Solent, needed expensive repairs. 17th century Yarmouth Castle continued to be an important military fortification, used both as a fortress but also as a transport hub and a stores depot. The repairs recommended in 1599 were carried out in the first years of the 17th century and a further £300 was invested in Yarmouth Castle and nearby Sandown Castle in 1609, including adding two angular buttresses along the walls facing the sea. A survey in 1623 by the castle's captain, John Burley, reported that the garrison comprised only four gunners and the captain, with the buildings in a "ruinous" state and the defences in need of repair; similar concerns were raised in 1625 and 1629. Suggestions that a half-moon battery should be added to the defences were not progressed, but in 1632 the parapets were raised in height and further lodgings and a long room for stores were constructed within the castle. Some of the stone used for this may have been reused from nearby Sandown, whose walls had been destroyed by the sea; before it was used at Sandown, the stone appears to have been taken from the local monasteries. Civil war broke out in 1642 between the followers of King Charles I and those of Parliament. Initially, Captain Barnaby Burley, a relative of John, and an ardent Royalist, held the castle on behalf of the King with a tiny garrison. Burley negotiated surrender terms, including that he initially be allowed to remain in the castle with armed protection, and the castle remained in the control of Parliament for the rest of the war. Early during the Interregnum