PRN 36815 On the 11th April 1643, a battle was fought on Ancaster Heath between the Royalists commanded by Cavendish and the Parliamentarians commanded by Lord Willoughby. The Parliamentarians were defeated and forced to retreat towards Lincoln, at which point they were pursued by the Royalists and routed. The exact location of the battlefield is not known. {1}{2} On 23 March 1643, the Royalist General Cavendish captured Grantham. On 11 April he was able to outmanoeuvre a Parliamentarian force of 1500 men under Lord Willoughby of Parham and the younger Holtham that was approaching Grantham and then pursue the force to Ancaster Heath where the Parliamentarians were routed. {3}