At length in 1651, after frequent complaints of the “pirates” of Scilly had been laid before Parliament, a fleet was sent under the command of Admiral Blake and Sir George Ayscue (Ascue, Ayscough, or Askew, I have never seen it spelt twice alike) to bring the islands into subjection. After the fleet had arrived within the roadstead, a day was lost through the treachery of a pilot called Nance, who, although “the most knowing pilot” of the place, led them to Norwithel, “affirming on his life” it was Tresco. Surprised, and exposed to the enemy’s fire, the Parliament men retreated to Tean, effecting a landing on Tresco the following day. [Illustration: CROMWELL’S CASTLE FROM CHARLES’S CASTLE] Here they took possession of an old breastwork on Carn Near, and erected an advanced battery to command Broad and Crow Sounds. It could reach any ship that went into or came out from St. Mary’s Harbour, and generally with effect, for ships must often pass very near in order to avoid rocks or flats. The King’s party in consequence soon became so distressed that a messenger was sent for orders to the Prince in Holland, and brought back permission from him for the Cavaliers to surrender and make the best terms they could for themselves. Eight hundred soldiers were taken prisoner with Sir John Granville, and officers “enough to head an army.” Soon after the reduction of the islands, a strong circular tower, now known as Oliver Cromwell’s Castle, was built on Tresco. It was so placed, low down on the shore, that its guns could sweep the surface of the water for a great distance. It was constructed in part from the materials of a much older fortress on the hill above, called Charles’s Castle, a building of great strength, but in an unfavourable situation for defence. After the Restoration, when the Godolphins were again in power in Scilly, Duke Cosmo records that the garrison on St. Mary’s was reduced from six hundred to two hundred men. He mentions also that twenty soldiers were employed to guard Cromwell’s castle (or “the Castle of Bryer,” as he calls it). Later this fortress was allowed to fall into decay, for in 1740, when England was at war with Spain, it had to be “put into a state of good defence,” but apparently no garrison was kept there for long, and it again suffered from neglect. During this same war with Spain, many batteries were erected on the Hugh of St. Mary’s (now known as Garrison Hill), and a strong entrance gateway to the fortifications was built in 1742. Since then the military establishment seems to have been gradually reduced. In 1822 it consisted only of a Lieutenant-Governor, a master-gunner with four others under him, and two or three aged sergeants. In 1857 “five invalids” manned the fortifications, and in 1863 the fort was dismantled.