Early in the English Civil War,
Scarborough, its castle and strategic supply port were first held for Parliament by Sir
Hugh Cholmley. In March 1643, he was persuaded to change sides. Cholmley actually lost the castle in a bloodless takeover by his own
cousin, Captain
Browne Bushell, in the same month while away at
York, but persuaded him to give it back. Cholmley ordered the castle to be refortified, including the establishment of the South Steel Battery for
artillery.
Royalist stronghold After March 1643, although Cholmley was the only Royalist commander at work in east and north
Yorkshire, his forces felt so secure at Scarborough that they could move almost freely throughout the region, targeting Parliamentarian positions. In May, Cholmley's
cavalry moved north of
Whitby, 20 miles away, and pillaged the estate of the Earl of Mulgrave, a loyal Parliamentarian. In June, Cholmley captured the marketplace at
Beverley, some 30 miles from the castle, and from September to October 1643 he was present at the unsuccessful second
Siege of Hull. Though Cholmley's activities were a nuisance to the Parliamentarians, these victories were never decisive, and Parliament considered the King's south-western strongholds far more important targets. However,
piracy ensured that Scarborough became a priority. The port was a safe haven for Royalist ships which attacked and plundered ships taking coal to London, which would become a more pressing concern as winter approached. The port was also a safe place for arms to be imported for the Royalist armies. The Royalist failure at Hull and the entry of the Scottish
Covenanters into the war on Parliament's side in late 1643 resulted in a run of Parliamentarian victories across Yorkshire. On 2 July 1644, the Parliamentarians and Covenanters won a great victory at the
Battle of Marston Moor. The next day, the
Marquess of Newcastle, the King's captain-general in the north, and several of his senior officers, took ships from Scarborough and went into exile on the continent, abandoning the fight. Two weeks later, the city of York surrendered. Scarborough was left the most important Royalist garrison in Yorkshire, but many of Cholmley's garrison deserted and the castle fell into disrepair. In August,
Lord Fairfax's Parliamentarian force reached the edge of the town. Cholmley bought time to upgrade the castle defences by opening surrender negotiations, an act that would allow him to hold out for a year. ==Siege==