command of a choice regiment of horse to serve the king' (An Examination Examined, 1645, p. 15). At the defeat of the royalists at Willoughby Field in Nottinghamshire (5 July 1648) Hacker commanded the left wing of the parliamentary forces (Memoirs of Col. Hutchinson, ed. 1885, p. 384). During the trial of Charles I, Hacker was one of the officers specially charged with the custody of the king, and usually commanded the guard of halberdiers which escorted the king to and from Westminster Hall. He was one of the three officers to whom the warrant for the king's execution was addressed, was present himself on the scaffold, supervised the execution, and signed the order to the executioner (Trials of the Regicides, pp. 217-26, ed. 1660). According to Herbert he treated the king respectfully (Memoirs of Sir Thomas Herbert, ed. 1702, pp. 121, 132, 135). Hacker commanded a regiment under Cromwell in the Scotch war. Cromwell wrote to Hacker, 25 Dec. 1650, rebuking him for slightingly describing one of his subalterns as a better preacher than fighter, and telling him that he expects him and all the chief officers of the army to encourage preaching (Carlyle Letter clxii). Hacker was a religious man, but a strict presbyterian and a persecutor of the quakers (Fox, Journal, p. 136). He confessed shortly before his death 'that he had formerly born too great a prejudice in his heart towards the good people of God that differed from him in judgment' (A Collection of the Lives, Speeches, &c., of those Persons lately Executed, 1661, p. 170). While Cromwell lived he was a staunch supporter of the protectorate, arrested Lord Grey in February 1655, and was employed in the following year to suppress the intrigues of the cavaliers and Fifth-monarchy men in Leicestershire and Nottinghamshire (Thurloe, iii. 148, 395, iv. 248, 598, 720). In Richard Cromwell's parliament Hacker represented Leicestershire, but was a silent member. 'All that have known me,' he said at his execution, 'in my best estate have not known me to have been a man of oratory, and God hath not given me the gift of utterance as to others' (Lives, Speeches, &c., p. 175).
In the troubled period preceding the Restoration he followed generally the leadership of his neighbour Sir Arthur Haslerig, whose 'creature' Mrs. Hutchinson terms him (Memoirs, ii. 179; Clarendon State Papers, iii. 53). By Haslerig's persuasion he, first of all the colonels of the army, accepted a new commission from the hands of the speaker of the restored Long parliament, and was among the first to own the supremacy of the civil power over the army (Ludlow, Memoirs, ed. 1751, p. 253; Commons' Journals, vii. 675). He opposed the mutinous petitions of Lambert's partisans in September 1659, and, after they had expelled the parliament from Westminster, entered into communication with Hutchinson and Haslerig for armed opposition (Hutchinson, Memoirs, ii. 234 ; Baker, Chronicle, ed. 1670, p. 691). After the triumph of the Rump he was again confirmed in the command of his regiment, and seems to have been still in the army when the Restoration took place (Commons' Journals, vii. 824). On 5 July 1660 he was arrested and sent to the Tower, and his regiment given to Lord Hawley (Mercurius Publicus, 28 June-5 July 1660, ib. 5-12 July). The House of Commons did not at first except him from the Act of Indemnity, but during the debates upon it in the lords the fact came out that the warrant for the execution of the king had been in Hacker's possession. The lords desired to use it as evidence against the regicides, and ordered him to produce it. Mrs. Hacker was sent to fetch it, and, in the hope of saving her husband, delivered up the strongest testimony against himself and his associates (Journals of the House of Lords, xi. 100, 104, 113 ; Hutchinson, Memoirs, ii. 253). The next day (1 Aug. 1660) the lords added Hacker's name to the list of those excepted, and a fortnight later (13 Aug.) the House of Commons accepted this amendment (Journals of the House of Lords, xi. 114; Commons' Journals, viii. 118). Hacker's trial took place on 15 Oct. 1660. He made no serious attempt to defend himself: 'I have no more to say for myself but that I was a soldier, and under command, and what I did was by the commission you have read' (Trials of the Regicides, p. 224). He was sentenced to death, and was hanged on 19 Oct. 1660. His body, instead of being quartered, was given to his friends for burial, and is said to have been interred in the church of St. Nicholas Cole Abbey, London, the advowson of which was at one time vested in the Hacker family (Cal State Papers, Dom. 1660-1, p. 316; Briscoe, Old Nottinghamshire, p. 134). This concession was probably due to the signal loyalty of other members of his family. One brother, Thomas Hacker, was killed fighting for the king's cause (Briscoe, p. 134). Another, Rowland Hacker, was an active commander for the king in Nottinghamshire, and lost his hand in his service (Cal. State Papers, Dom. 1660-1, p. 339 ; Hutchinson, i. 262, 312).
Hacker married (5 July 1632) Isabella Brunts of East Bridgeford, Nottinghamshire, by whom he had one son, Francis, an officer in his father's regiment, and a daughter, Anne.
His estate passed to the Duke of York, but
