25 March 1644 (Life of Newcastle, p. 355; Warburton, Prince Rupert, ii. 370). When Newcastle was obliged to shut himself up in York, Lucas and the cavalry were sent to quarter in the midland counties and take part in attempts to relieve the besieged. He joined Rupert on his march to York, and was one of the commanders of the left wing in the battle of Marston Moor, where he was taken prisoner (Vicars, God's Ark, ii. 276).
Lucas was exchanged during the winter of 1644, and became governor of Berkeley Castle (Warburton, iii. 38, 66). The garrison was inadequate and unruly, and the castle was taken by Colonel Rainsborough on 25 Sept. 1645, after nine days' siege (Sprigge, Anglia Rediviva, p. 136, ed. 1854; Hist. MSS. Comm. 9th Rep. ii. 437). On 28 Nov. 1645 the king appointed Lucas lieutenant-general of all his cavalry; he accompanied Lord Astley to Worcester in December 1645, in hopes of raising a new army, shared in Astley's defeat at Stow-in-the-Wold, March 1646, and was again taken prisoner (Vicars, God's Ark, p. 399; Black, Oxford Docquets, p. 275). Fairfax seems to have released him on parole, and Lucas subsequently compounded for his estates for the sum of 508l 10s., and engaged not to bear arms against the parliament in future (Rushworth, vii. 1160; Fairfax Correspondence, iii. 57; Cal. of Compounders, p. 1821). When the Earl of Norwich and the Kentish insurgents entered Essex, Lucas by his persuasions induced the Essex royalists to join them, instead of accepting the indemnity offered by parliament (July 1648; Rushworth; Hist. MSS. Comm. Beaufort MSS. 12th Rep. p. 21). In the seizure and defence of Colchester he played the foremost part, on account of his local influence and his military skill, which was far superior to that of his nominal commander the Earl of Norwich (ib. pp. 23-8; Matthew Carter, True Relation of the Expedition of Kent, Essex, and Colchester in 1648, pp. 121, 130). One parliamentary account accuses him of cruelty to the inhabitants of Colchester, and Clarendon speaks of his 'rough and proud nature which made him during the time of their being in Colchester more intolerable than the siege or any fortune that threatened them' (Rebellion, xi. 108; Colchester's Tears, 1648, 4to, p. 10). On the other hand Carter represents Lucas as 'tender of injuring his countrymen' and commiserating their sufferings, and a parliamentary newsletter describes him as carrying himself more moderately than the other royalist leaders (Carter, pp. 149, 160; Rushworth, vii. 1181). When Colchester capitulated (27 Aug. 1648) the superior officers were obliged to 'render themselves to mercy,' and Lucas was condemned to death by a court-martial. The sentence was the result of the exasperation felt by the puritan officers against the authors of the second civil war, but can neither be regarded as a breach of the capitulation, nor be specially attributed to Fairfax. Parliament by its votes of 20 June 1648 had declared all who took part in the new civil war guilty of high treason, and Ireton used this argument to justify the sentence. 'I am no traitor,' answered Lucas, 'but a true subject to my king and the laws of the kingdom. … I do plead before you all the laws of this kingdom. I have fought with a commission from those that were my sovereigns, and from that commission I must justify my action' (An Account of the Death of Sir Charles Lucas, &c., Clarke MSS.; cf. Gardiner, Great Civil War, iii. 459). Lucas and his fellow-prisoner, Sir George Lisle [q. v.], were shot on 28 Aug. in the castle yard at Colchester, and buried in the vault of the Lucas family in the north aisle of St. Giles's Church, Colchester (Morant, Essex, i. 72; Carter, p. 234). Twelve years later, on 7 June 1661, the funeral of Lucas and Lisle was solemnly celebrated by the town of Colchester, and a stone was placed by Lord Lucas on their tomb, with an inscription stating that they were, 'by the command of Sir Thomas Fairfax, in cold blood barbarously murdered' (ib. p. 235; Mercurius Publicus, 6-13 June 1661).
Lucas and Lisle are celebrated in two contemporary poems: 'The Loyal Sacrifice,' 8vo, 1648, and 'An Elegy on the Murder committed at Colchester upon Sir C. Lucas and Sir G. Lisle,' 4to, 1648 (cf. Edward Howard's absurd epic on the civil wars entitled Caroloiades Redivivus, 8vo, 1695)
A portrait of Lucas, by Robert Walker, is in the possession of Lord Lyttelton. Engraved portraits are in Warburton's 'Prince Rupert' and in the illustrated edition of Clarendon's 'Rebellion,' said to be from a painting by Dobson (see Cat. of Sutherland Collection in the Bodleian Library, p. 607, and Granger, Biog. Hist. 1779, ii. 267).
Lucas was reputed to be one of the best cavalry leaders in the king's army. Even Clarendon, who judges him with undue severity, describes him as 'very brave in his person, and in a day of battle a gallant man to look upon and follow' (Rebellion, xi. 108). According to his sister, Lucas 'naturally had a practical genius to the warlike arts, as natural poets have to poetry, but his life was cut off before he could arrive at the true perfection thereof.' He left a 'Treatise