It was in January of the following year that a young officer—Colonel Cromwell—determined to make an effort to rescue Lady Bankes, and riding with a specially picked troop from Oxford he passed through the enemy without its being discovered that he was a Royalist until he arrived at Wareham, the governor of which fired upon the troop. A fight ensued, but the daring troopers speedily captured the governor and other leading men, and rode off to Corfe Castle, only, however, to find that between them and the besieged lay a strong force of the enemy. They did not hesitate, but prepared instantly for the fight, and the besieged, cheering them loudly, made ready to sally forth and assist them.
Afraid of being caught between the two Royalist parties, the besiegers retired, and Colonel Cromwell rode up in triumph to the castle walls, and handed over to Lady Bankes, for safe custody, the Governor of Wareham and other prisoners whom he had taken.
Greatly to Colonel Cromwell's surprise, Lady Bankes declined to avail herself of the opportunity for escape which he had contrived, declaring that she would defend the castle as long as she possessed ammunition. Thinking that he could render the king greater service in the open than in a besieged castle, Colonel Cromwell rode off with his troop, but losing his way he and many of his men were captured by the enemy. Those who evaded capture made their way back to Corfe Castle, and assisted in its defence.
Days passed without the enemy improving his position in the slightest degree, and Lady Bankes would have kept the royal flag flying for many months more, had there not been traitors in the castle. Colonel Lawrence, who had gallantly assisted in the first defence of Corfe Castle, was persuaded by the Governor of Wareham to help him to escape, and to accompany him on his flight. The treachery of Lawrence was a heavy blow for Lady Bankes, but she did not despair, believing it impossible that any other of her friends would turn traitor. Unfortunately she was mistaken. An officer, who had hitherto been loyal and energetic as Colonel Lawrence, secretly sent word to the officer commanding the besieging force that if protection were given him he would deliver up the castle. The proposal was welcomed, and after much secret correspondence it was settled that fifty men of the Parliamentarian army should disguise themselves as Royalists, and be admitted into the castle by the traitor.
This plan succeeded. The men were admitted without arousing any suspicion, and not until the following morning did the garrison discover that they had been betrayed. A brief fight ensued, but resistance was useless, and with a sad heart Lady Bankes surrendered the castle which she had so nobly defended for nearly three years.
The Parliamentarian officer who accepted the surrender was a humane man, and took care that his troops should not fulfil their vow to put to death every man, woman and child found in the castle. After the place had been plundered, an attempt was made to destroy it, but the walls were so massive that its destruction was impossible, and to-day much of it is still standing.
Lady Bankes was not kept prisoner for long, and Oliver Cromwell ordained that she should not be made to suffer for her loyalty and bravery. Throughout the Commonwealth the heroine of Corfe Castle lived peacefully, and did not die until Charles II. had been upon the throne nearly a year. She died on April 11, 1661, and in Ruislip Church, Middlesex, there is a monument, erected to her memory by her son, Sir Ralph Bankes, on which is inscribed a record of her brave defence.