Charles Lucas Sir Charles Lucas ( 1613 – 28 August 1648 ) was an English soldier , a Royalist commander in the English Civil War . Biography . Lucas was the son of Sir Thomas Lucas of Colchester , Essex . As a young man Lucas served in the Netherlands under the command of his brother , and in the " Bishops ' Wars " he commanded a troop of horses in King Charles I ' s army . In 1639 he was knight ed . At the outbreak of the First English Civil War , Lucas naturally took the king ' s side , and at the first cavalry engagement , the Battle of Powick Bridge , he was wounded . Early in 1643 Lucas raised a regiment of horse , with which he defeated Middleton at Padbury on 1 July . In January 1645 he commanded the forces attacking Nottingham , and soon afterwards , on Prince Rupert ' s recommendation , he was made lieutenant - general of the Duke of Newcastle ' s Northern army . When Newcastle was shut up in York , Lucas and the cavalry remained in the open country , and when Rupert ' s relieving army crossed the mountains into Yorkshire he was quickly joined by Newcastle ' s squadrons . At the Battle of Marston Moor Lucas swept Fairfax ' s Yorkshire horse before him , but later in the day he was taken prisoner , in a battle won decisively by Parliament . Exchanged for Parliamentary prisoners during the winter , he defended Berkeley Castle for a short time against Thomas Rainsborough , but was soon back in the field . As lieutenant - general of all the horse , he accompanied Lord Astley in the last campaign of the first war and , taken prisoner again at Stow - on - the - Wold , he agreed not to bear arms against Parliament in the future . During the Second English Civil War he broke this parole when he took a prominent part in the seizure of Colchester in 1648 . After a three - month siege , the town surrendered to Fairfax on 28 August . When Colchester capitulated 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 " . Lucas and his fellow - prisoner , Sir George Lisle , were shot on 28 August 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 . 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 " . By way of reparation , Lucas was awarded a posthumous peerage in 1666 . Contemporary reputation . 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 " . 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 of the Arts of War " , but being written in cipher it was never published . To his military gifts Lucas added a devotion to the king ' s cause , which he sometimes expressed in singularly high - flown and poetical language . Family . He was the youngest son of Sir Thomas Lucas ( d . 1625 ) of Colchester , Essex , and Elizabeth , daughter of John Leighton of London , gentleman . His elder brothers Sir John Lucas , and Sir Thomas Lucas ( d . 1649 ) fought for the King . His younger sister the future Margaret , Duchess of Newcastle , described her brother ' s youthful career in her autobiography . Arts . Lucas and Lisle are celebrated in two contemporary poems : A portrait of Lucas , by Robert Walker , was in the possession of Lord Lyttelton in 1900 . Engraved portraits are in Warburton ' s " Prince Rupert " and in the illustrated edition of Clarendon ' s " Rebellion " , said to be from a painting by William Dobson .