During the First English Civil War Lincoln was besieged between 3 May and 6 May 1644 by Parliamentarian forces of the Eastern Association of counties under the command of the Earl of Manchester. On the first day, the Parliamentarians took the lower town. The Royalist defenders retreated into the stronger fortifications of the upper town, which encompassed and incorporated Lincoln Castle and Lincoln Cathedral. The siege ended four days later when the Parliamentarian soldiers stormed the castle, taking prison the Royalist governor, Sir Francis Fane, and what remained of his garrison.
On 6 May, Lincoln Castle was stormed with scaling ladders, which proved to be too short, but the Parliamentarians nonetheless managed to scale the walls and enter the castle. The Royalists fled from the parapets, begging for quarter, which was granted. Parliamentarian casualties were eight killed and about 40 wounded. The Royalists had about 150 killed and between 650 and 800 taken prisoner.