Sexby was born in Suffolk in 1616 but little else is known about his life before the English Civil War. Reportedly he was a son of a gentleman, had been an apprentice as a grocer in London and may have had family connections to Cromwell. In 1643 he was a trooper in Cromwell's Roundhead cavalry regiment (nicknamed the Ironsides).
In 1647, being still a private in the same regiment, now commanded by Sir Thomas Fairfax, he took a leading part in the movement against disbanding the army, and was one of the three soldiers charged with the letter from the army to their generals which Skippon brought before the House of Commons on 30 April 1647. He became one of the leaders of the "Agitators", and acted as their chief spokesman in the Putney Debates of the Army Council in October 1647. His speeches were very vigorous and effective, opposing all compromise with King Charles I and demanding the immediate establishment of manhood suffrage. He may have been involved in the capture of the king at Holdenby House in 1647.
Sexby appears to have left the army about the close of 1647, but happening to be present at the Battle of Preston, with a letter from the Levellers leader John Lilburne to Cromwell, he was entrusted with a despatch from Cromwell to the speaker of the House of Commons announcing his victory. The House of Commons voted him £100 as a reward. In February 1649 Parliament entrusted him with the duty of arresting the Scottish commissioners, for which he was ordered £20. He was also appointed governor of Portland, is henceforth described as Captain Sexby, and was more than once charged with commissions requiring courage and dexterity.
In June 1650, at Cromwell's suggestion, Sexby was charged to raise a foot regiment for service in Ireland, but when completed it was ordered to Scotland. Sexby, who held the rank first of lieutenant-colonel and then of colonel, took part with his regiment in the siege of Tantallon Castle in February 1651. In June 1651 he was tried by court-martial for detaining the pay of his soldiers, and lost his commission.
A few months later Cromwell and the intelligence committee of the Council of State sent Sexby on a mission to France. He was charged to give an account of the political condition and the temper of the people. He negotiated with the Prince de Conti and the Frondeurs of Guienne, to whom he proposed an adaptation of the Agreement of the People as the basis of a republican constitution for France, and with the Huguenots of Languedoc. One of his emissaries was captured, and (according to Edmund Ludlow), Sexby had a narrow escape himself. Sexby returned to England about August 1653, and on 23 August 1654 was ordered £1,000 for his expenses during his mission.
Sexby was eager for an Anglo-Spanish league against France, and hoped to obtain the command of the levies which it was proposed to send to the support of the Frondeurs. Cromwell's abandonment of the projects against France, and still more his assumption of The Protectorate, caused a breach with Sexby, who allied himself with the disaffected republicans, disseminated pamphlets against the Protector, and took a leading part in the schemes for a joint rising of royalists and levellers in the spring of 1655. In February 1655 Cromwell's officers in the west of England were in hot pursuit of Sexby, but he succeeded in escaping to Flanders. At Antwerp he made the acquaintance of Colonel Robert Phelips and other royalists, to whom he described Cromwell as a false, perjured rogue, and affirmed that, if proper security for popular liberties were given, he would be content to see Charles II restored.
Sexby also sought an interview with Count Fuensaldanha, second in command of the Army in the Spanish Netherlands, to whom he revealed all he knew of Cromwell's foreign plans and of the expedition to the West Indies, and from whom he asked a supply of money and the assistance of some of the Irish troops in the Spanish service to raise an insurrection in England. Fuensaldanha sent Sexby to Spain that his proposals might be considered by the Spanish council (June 1655), and he returned again about December with supplies of money and conditional promises of support. Father Peter Talbot, who acted as interpreter in Sexby's dealings with Fuensaldanha, communicated his proposals to Charles II, urging the King to come to an agreement with Spain, and to use Sexby and his party. In December 1656 Sexby presented a paper of proposals to Don John of Austria, offering to raise a civil war in England, and requesting a thousand Irish foot and four hundred horses (for which he undertook to provide troopers). The royalists were to assist, but he stipulated "that no mention be made of the king before such time Cromwell be destroyed, and till then the royalists that shall take arms shall speak of nothing but the liberty of the country, according to the declaration whereof I have spoken with the King of England's ministers".
The Protector's government through its agents abroad was kept well informed of Sexby's negotiations with Spain, and a number of his intercepted letters, written under the assumed names of "Brookes" and "Hungerford", were in its hands. In Cromwell's speech at the opening of the Second Protectorate Parliament (17 September 1656), he informed them of Sexby's plot, terming him "a wretched creature, an apostate from religion and all honesty". The assassination of Cromwell was an essential preliminary to the success of the rising. Sexby sent over "strange engines" for the purpose, but his agents missed their opportunities, and in January 1657 an attempt to fire the Palace of Whitehall led to the arrest of their leader, Miles Sindercombe. Still confident, Sexby devised new plots. "Be not discouraged", he wrote to Father Talbot, "for so long as Sexby lives there is no danger but Cromwell shall have his hands full, and I hope his heart ere long, for I have more irons in the fire for Cromwell than one. … Either I or Cromwell must perish".
A few months after the arrest of Sindercombe, an apology for tyrannicide, entitled Killing No Murder—which was dedicated to Cromwell—arrived in England from Holland. It was published by Sexby, probably with the assistance of Silius Titus, under the name of a former Army agitator called William Allen. In June he followed the pamphlet to England, to concert measures for carrying out its principles, and on 24 July, just as he was embarking for Flanders again, he was arrested "in a mean habit disguised as a countryman". He died in the Tower on 13 January 1658, "having been a while distracted in his mind and long sick". His body was buried in the cemetery near the Tower chapel two days later.
Killing No Murder was answered by Michael Hawke of the Inner Temple in Killing is Murder and no Murder, 1657, 4to. Sexby's authorship of the former is proved by internal evidence, and by his own confession made in the Tower. Captain Silius Titus, who was intimate with Sexby and may perhaps have assisted him in writing it, repudiated him after the Restoration.[a]
His wife visited him during his imprisonment in the Tower, but no other information about her has been found.
- Killing no Murder was reprinted in the Harleian Miscellany, ed. Park, iv. 289, and by Professor Henry Morley in his Famous Pamphlets.
- Marshall 2010.
- Firth 1897, p. 292 cites Rushworth, vi. 474; Clarke Papers, i. 430.
- Firth 1897, p. 292 cites Rushworth, i. 83.
- Firth 1897, p. 292 cites Rushworth, i. 227, 322, 329, 377.
- Firth 1897, p. 292 cites Rushworth, ii. 254; Commons' Journals, v. 680.
- Firth 1897, p. 292 cites Rushworth, vi. 152.
- Firth 1897, p. 292 cites Cal. State Papers, Dom. 1649–50, pp. 135, 155, 531.
- Firth 1897, p. 292 cites Cal. State Papers, 1650, pp. 206, 332, 352; Mecurius Politicus, p. 621.
- Firth 1897, p. 292 cites Clarke MSS.
- Firth 1897, p. 292 cites Ludlow, Memoirs, i. 415; Cal. State Papers, Dom. 1654, p. 160; Journal of Joachim Hane, 1896, pp. xiv–xvii.
- Firth 1897, p. 292.
- Firth 1897, p. 293 cites Thurloe, vi. 694, 829.
- Firth 1897, p. 293 cites Thurloe, iii. 162, 165, 195.
- Firth 1897, p. 293 cites Nicholas Papers, i. 299, 340, 347.
- Firth 1897, p. 293 cites Clarendon State Papers, iii. 271.
- Firth 1897, p. 293 cites Clarendon State Papers, iii. 281.
- Firth 1897, p. 293 cites Clarendon State Papers, iii. 315.
- Firth 1897, p. 293 cites Thurloe, State Papers, v. 37, 349, vi. 1, 33, 182.
- Firth 1897, p. 293 cites Carlyle, Cromwell's Speech, p. 5.
- Firth 1897, p. 293 cites Cromwelliana, p. 160; Clarendon State Papers, iii. 325, 327.
- Firth 1897, p. 293 cites Clarendon State Papers, iii. 331, 335, 339.
- Firth 1897, p. 293 cites Clarendon State Papers, iii. 343; Thurloe, vi. 311.
- Firth 1897, p. 293 cites Clarendon State Papers, Cromwelliana, p. 168; Clarendon State Papers, iii. 357, 362.
- Firth 1897, p. 293 cites Cromwelliana, p. 169.
- Marshall 2010 cites Mercurius Politicus
- Firth 1897, p. 293 cites Thurloe, vi. 560.
- Firth 1897, p. 293 cites Wood, Athenæ, iv. 624.
- Green, Jesse (7 May 2018). "Review: When the 'Light Shining' on Revolution Falters". The New York Times. Retrieved 27 May 2018.
- Marshall, Alan (September 2010) . "Sexby, Edward (c.1616–1658)". Oxford Dictionary of National Biography (online ed.). Oxford University Press. doi:10.1093/ref:odnb/25151. (Subscription or UK public library membership required.)
- This article incorporates text from a publication now in the public domain: Firth, Charles Harding (1897). "Sexby, Edward". In Lee, Sidney (ed.). Dictionary of National Biography. 51. London: Smith, Elder & Co. pp. 292–293.
- Marshall, Alan (February 2003). "Killing No Murder". History Today.