Maguire, Rory (Roger) (1619–48), Irish rebel, was the second son of Brian Roe, Lord Maguire of Enniskillen, and Rose, daughter of Art mac Baron O'Neill. The Maguires had supported the government during the Nine Years War (1594–1603) and had been rewarded with land in the Ulster plantation. Rory lived at Deerpark, Co. Fermanagh, sat as MP for Co. Fermanagh in 1640–41 and became a captain in the Irish army in 1640. In May 1640 he married Deborah, daughter of Sir Henry Mervyn of Hampshire and Christian Tuchet, daughter of Lord Castlehaven. She was also the widow of Leonard Blennerhasset (d. 1639), a wealthy local settler, which meant that the marriage brought Rory a castle at Hassetstown, Co. Fermanagh, and lands worth £900 a year. Maguire had two sons and a daughter.
Despite their favoured treatment as ‘deserving Irish’ and their cordial relations with protestant settlers, Rory and his brother Conor, second Lord Maguire (qv), were prime movers in the complex conspiracy which led to the outbreak of rebellion in the north of Ireland on 23 October 1641. Conor, whose role was to lead a simultaneous attack on Dublin castle, was arrested and eventually executed in London in 1645. Rory, whose task was to take control of Fermanagh and capture its strategically important fortresses, was only partly successful. A timely warning of what was to happen enabled the settlers under Sir William Cole (qv) to take refuge in and reinforce the castles of Enniskillen and Ballyshannon and other strongholds; Maguire was left in command only of the open ground. The rising in Fermanagh was accompanied by a number of atrocities, most notably the murder of Maguire's fellow MP Arthur Champion and others on 23 October, and Maguire's control over his forces appears to have been weak. Early in November, he joined Sir Phelim O'Neill (qv) at Newry where they issued a joint proclamation on 4 November in which they declared that the Irish were acting under a commission issued by the king. Later in the month, they joined once more in an unsuccessful bid to take Augher fort in Tyrone with the aid of a siege gun brought by Maguire from Fermanagh. About Christmas, the Fermanagh army under Maguire slaughtered many of the garrison and refugees in Tully castle, which had yielded on quarter, apparently in retaliation for the killing of the garrison of a Maguire castle which had been taken by assault some days previously.
Maguire became the governor of Fermanagh and in summer 1642 was made a colonel in Owen Roe O'Neill's (qv) Ulster army. He campaigned mainly in Fermanagh and Monaghan. The protestant garrison at Enniskillen continued to hold out and remained a constant irritant. In the autumn of 1645 O'Neill sent him with 500 men to raid and plunder the British garrisons on the upper Lough Erne. However, as he returned, Maguire was overtaken by British forces at Lowtherstown and was forced to abandon his plunder. The next year, he commanded the reserve at the battle of Benburb (5 June 1646), leading it against the Scots’ collapsing right flank to complete the encirclement of the Scottish army and to precipitate its destruction. After Benburb, Maguire led raids into British-held areas in east Ulster, before joining O'Neill in his campaigns in Leinster in the autumn of 1646. As O'Neill's relationship with the supreme council of the Catholic Confederation broke down in late 1646, Maguire was sent to secure Athlone for the Ulster army. Finding it in safe hands, he led his detachment into Connaught where he raided the lands of the catholic royalist Ulick Burke (qv), marquess of Clanricarde. He campaigned under O'Neill in Connaught for much of 1647.
However, in August 1647 the supreme council beseeched O'Neill to return to Leinster to protect the province from protestant attacks. Reluctantly, O'Neill agreed and set up camp in Kilbeggan, Co. Westmeath, where he began recruiting troops and gathering materials for the upcoming campaign. Here Maguire quarrelled so vigorously with O'Neill over the payment of troops that the general ordered his arrest and court-martialled him in the local church. Many of O'Neill's men distrusted the supreme council and were very unhappy at O'Neill's decision to return to Leinster. This issue, rather than money, was probably the real reason for Maguire's dispute with O'Neill. A highly charged hearing ensued and many officers in the Ulster army took the stand to denounce the supreme council. After the court martial, Maguire and his supporters, about five or six regiments, drew up their forces and threatened to desert. However, at this point, Maguire's erstwhile comrade-in-arms Richard O'Ferrall (qv) boldly strode across to Maguire, berated him for his behaviour and beat him with the back of his sword, causing the mutiny to peter out. This dispute did no long-term damage to Maguire's relationship with O'Neill, who continued to regard Maguire highly.
The Ulster army campaigned for the supreme council in Leinster in the autumn of 1647, but in the summer of 1648 civil war broke out within the confederation, with O'Neill opposing the supreme council's truce with protestant forces. Maguire played a prominent role in the skirmishes and evasive manoeuvrings that occurred between the two sides in the midlands, taking Banagher in a surprise attack with 400 men. That winter, the Ulster army withdrew to the north, where Maguire was killed in a minor skirmish at Jamestown, Co. Leitrim.