That an enterprise correspondent to men's expectations might be undertaken, the prince resolved to lay siege to Bristol, the second town for riches and greatness in the kingdom.
Nathaniel Fiennes, son of Lord Say he himself, as well as his father, a great parliamentary leader was governor, and commanded a garrison of two thousand five hundred foot, and two regiments, one of horse, another of dragoons.

The fortifications not being complete or regular, it was resolved by Prince Rupert to storm the city, and next morning, with little other provisions suitable to such a work besides the courage of the troops, the assault began.

The Cornish in three divisions attacked the west side, with a resolution which nothing could control; but though the middle division had already mounted the wall, so great was the disadvantage of the ground, and so brave the defence of the garrison, that in the end the assailants were repulsed with a considerable loss both of officers and soldiers.

On the prince's side, the assault was conducted with equal courage, and almost with equal loss, but with better success.

One party, led by Lord Grandison, was indeed beaten off, and the commander himself mortally wounded: another, conducted by Colonel Bellasis, met with a like fate: but Washington, with a less party, finding a place in the curtain weaker than the rest, broke in, and quickly made room for the horse to follow.