Royal Fort - Prince Rupert's Gate. Near this spot, on 11 September 1645, Prince Rupert of the Rhine, nephew of King Charles I and Commander of the Royalist garrison of Bristol, surrendered the City to Sir Thomas Fairfax, Commander of Parliament's New Model Army and to Oliver Cromwell, his Master of Horse. This brick gatehouse is the most substantial remaining portion of the Royal Fort, a pentagonal bastion reconstructed by Prince Rupert after he had captured Bristol in 1643. Because of Bristol's strategic military position and value as a port, its capture by the Parliamentarian forces was a turning point in the Civil War.