Due to its strategic position, Brigg was fortified by Royalist forces during the civil war. After the Battle of Winceby in 1643, Parliamentarian forces attacked and seized the garrison on their way to help relieve the siege of Hull. Sir John Nelthorpe, a local landowner who had been a member of Parliament during the Protectorate, bequeathed some of his estate in 1669 for the foundation and maintenance of a free school in the town. Four other local gentlemen established a chapel of ease in Bigby Street in 1699, restoring church presence in the town after 150 years of absence.