On 4 Jan. 1650 the parliament appointed him president of Munster (Cal. State Papers, Dom. 1649–50, pp. 476, 502; Commons' Journals, vi. 343). When Cromwell was recalled to England he appointed Ireton to act as his deputy (29 May 1650). Parliament approved the choice (2 July), and appointed Ludlow and three other commissioners to assist Cromwell in the settlement of Ireland (ib. vi. 343, 479). All Connaught, the greater part of Munster, and part of Ulster still remained to be conquered. Ireton began by summoning Carlow (2 July 1650), which surrendered on 24 July. Waterford capitulated on 6 Aug. and Duncannon on 17 Aug. Half Athlone was taken (September) and Limerick was summoned (6 Oct.), but as the season was too late for a siege it was merely blockaded. Ireton's army went into winter quarters at Kilkenny in the beginning of November (Gilbert, Aphorismical Discovery, iii. 218–25; Borlase, Hist. of the Irish Rebellion, ed. 1743, App. pp. 22–46). The campaign of 1651 opened late. On 2 June Ireton forced the passage of the Shannon at Killaloe, and the next day came before Limerick, which did not capitulate till Oct. 27. In announcing the fall of Limerick he congratulated the parliament that the city had not accepted the conditions tendered it at the beginning of the siege. This obstinacy, he said, had served to the greater advantage of the parliament ‘in point of freedom for prosecution of justice—one of the great ends and best grounds of the war;’ and also ‘in point of safety to the English planters, and the settling and securing of the Commonwealth's interest in this nation’ (Gilbert, iii. 265). Twenty-four persons were excepted from mercy, some on account of their influence in prolonging the resistance, others as ‘original incendiaries of the rebellion, or prime engagers therein’ (ib. p. 267). Seven of the excepted were immediately hanged, and others reserved for future trial by civil or military courts. Ireton's severity, however, was not indiscriminate. His ‘noble care’ of Hugh O'Neill, the governor of Limerick, is praised by the author of the ‘Aphorismical Discovery’ (iii. 21). He cashiered Colonel Tothill for breaking a promise of quarter made to certain Irish prisoners, and executed two other officers for ‘the killing one Murphy, an Irishman’ (Borlase, App. p. 34; Several Proceedings in Parliament, 31 July–7 Aug. 1651). The distinction he drew between the different classes among his opponents is clearly set forth in his letter of summons to Galway (7 Nov. 1651; Mercurius Politicus, p. 1401). Ireton's policy as to the settlement of Ireland was a continuation of Cromwell's. He regarded the replantation of the country with English colonists as the only means of permanently securing its dependence on England. He ordered the inhabitants of Limerick and Waterford to leave those towns with their families and goods within a period of from three to six months, on the ground that their obstinate adherence to the rebellion and the principles of their religion rendered it impossible to trust them to remain in places of such strength and importance. He promised, however, to show favour to any who had taken no share in the massacres with which the rebellion began, and to make special provision for the support of the helpless and aged (Borlase, p. 345). Toleration of any kind he refused, believing that the catholics were a danger to the state, and that they claimed not merely existence but supremacy. He forbade all officers and soldiers under his command to marry catholic Irishwomen who could not satisfactorily prove the sincerity of their conversion to protestantism (1 May 1651; Several Proceedings in Parliament, p. 1458; Ludlow, Memoirs, p. 145).
In the civil government of Ireland and in the execution of his military duties Ireton's industry was indefatigable. Chief-justice Cooke describes him ‘as seldom thinking it time to eat till he had done the work of the day at nine or ten at night,’ and then willing to sit up ‘as long as any man had business with him.’ ‘He was so diligent in the public service,’ says Ludlow, ‘and so careless of everything that belonged to himself, that he never regarded what clothes or food he used, what hour he went to rest, or what horse he mounted’ (ib. p. 143). Immoderate labours and neglect of his own health produced their natural result, and after the capture of Limerick Ireton caught the prevailing fever, and died on 26 Nov. 1651. On 9 Dec. parliament ordered him a funeral at the public expense (Commons' Journals, vii. 115). His body was brought to Bristol, and conveyed to London, where it lay in state at Somerset House, and was interred on 6 Feb. 1652 in Henry VII's Chapel in Westminster Abbey (Chester, Westminster Abbey Registers, p. 522; Cal. State Papers, Dom. 1651–2, pp. 66, 276). His funeral sermon was preached by John Owen, and published under the title of ‘The Labouring Saint's Dismission to his Rest’ (Orme, Life of Owen, p. 139). An elegy on his death is appended to Thomas Manley's ‘Veni, Vidi, Vici’ (12mo, 1652). A magnificent monument was erected with a fervid epitaph, which is printed in Crull's ‘Antiquities of Westminster’ (ed. 1722, ii. App. p. 21). ‘If Ireton could have foreseen what would have been done by them,’ writes Ludlow, ‘he would certainly