During the English Civil War Bristol was a key port on the west coast of England and considered strategically important by both Royalists and Parliamentarians. Initially, the leadership of Bristol wanted to keep the city neutral in the conflict. In 1642, city officials implored Thomas Essex not to occupy the city with his Parliamentarian forces. The city was weakly defended, and Essex entered without much resistance. During the conflict, Bristol was used as a receiving point for the Royalists to accept reinforcements from Ireland. (Wikipedia Article).
BNJ Reference: H. W. Morrieson, ‘The coinage of Bristol, 1643-1645’, 18 (1925-26), 135-57, 3 pls.