MacDonnell, Sir James MacSorley (d. 1601), Gaelic chieftain, was the third son of Sorley Boy MacDonnell (qv) and Mary O'Neill, daughter of Con O'Neill (qv), 1st earl of Tyrone. Following Sorley Boy's death (January 1590), James became captain of the Route and part of the Glens of Antrim under his cousin Angus, who was head of the Ian Mor, a clan holding land in both Antrim and the western isles of Scotland. Almost immediately he was confronted by the efforts of the MacQuillans to recover by force the lands they had previously held in the Route before the MacDonnells displaced them. Low-level conflict soon prevailed and both sides appealed to the government, which, eager to check the MacDonnells, favoured their rivals.
This provoked a rift between James and Angus, for the latter (under pressure from the Scottish government) had no stomach for alienating the English, leaving his cousin isolated. James's strategy of placing the Irish interests of the MacDonnells before their Scottish interests was correct, as their true power base now lay in Ireland. Over the next decade he displayed considerable single-mindedness and skill, both military and diplomatic, in establishing the primacy of the MacSorleys in north-east Ulster. Despite his achievements he has been overshadowed by his father and brother, lacking their capacity for naked survival. Angus was the stronger for the moment, and – embarrassed at his cousin's aggressions – landed in Ireland in May 1593 and imprisoned him. James's defiance of the government had been sponsored by Hugh O'Neill (qv), 2nd earl of Tyrone, who was also on collision course with the crown but who for now preferred combat by proxy. Within a few weeks Tyrone compelled Angus to release James. By September James had driven the MacQuillans completely from the Route, resulting in his indictment for treason. At Tyrone's behest he also raided the Glens and Clandeboye and threatened the English garrison at Carrickfergus, violently signifying his independence from his nominal clan leader.
By the start of 1595 James's brother, Randal MacDonnell (qv), was a prisoner in Dublin castle, dramatically altering the situation. James tried, or at least affected, to maintain a position of neutrality between Tyrone, now in open rebellion, and the crown, travelling to Dublin in February 1596 to negotiate with the lord deputy. Tyrone, unhappy at James's rapprochement with the government, marched against him in June. By then James had secured Randal's release, enabling him to fall in behind Tyrone once more. Nonetheless, Tyrone only intermittently held sway over his resolutely independent neighbour; the English never entirely gave up on James. His self-aggrandising feuds – with Shane MacBryan, Donnell O'Cahan (qv), and especially Angus – severely impaired the cohesion of Tyrone's confederacy. Indeed, in August he conquered the Glens from Angus, taking advantage of the latter's momentary weakness in Scotland after King James VI's decision to launch a campaign against him. In October James wrote to the king, offering aid, before audaciously claiming that Angus was illegitimate and that he was rightful owner of the Clan Ian Mor's Scottish lands. Anxious to keep the MacDonnells divided, the king invited James to Edinburgh, where he knighted him on his arrival in May 1597 and granted him land.
Now in control of his clan's Irish lands, James moderated his attitude towards the English once more. However, during the autumn of 1597 a series of tit-for-tat cattle raids occurred between his men and the Carrickfergus garrison under Sir John Chichester. On 4 November he met with Chichester near Carrickfergus to resolve the matter. Egged on by his men, Chichester rashly decided to attack. The opposing forces were roughly equal in number, but the English were weary and short of gunpowder. Moreover, James had hidden some 800 musketeers and bowmen two miles back. His vanguard retreated from hill to hill, fending off the assault, until they reached the ambush area, by which time the attackers were depleted of gunpowder. The English were annihilated, Chichester numbering among the slain. Paradoxically, this brilliant victory had the effect of weakening James's position, as it limited his options and probably contributed to his ultimate demise; relations with the English never fully recovered. He continued to affirm covertly his loyalty to the crown, but for the moment was dependent on Tyrone, to whose daughter, Alice, he was soon after betrothed.
However, his amity with the king of Scotland could yet secure him pardon. It also gave him some leverage with Tyrone, who purchased his provisions and munitions in Scotland and hoped to recruit mercenaries there. Hence in December 1597 James travelled once more to Edinburgh, where he was warmly received by the king. On returning to Ireland he surprised Olderfleet castle in January 1598, and in August fought at the battle of Yellow Ford, where Tyrone routed a royal force sent to relieve Blackwater fort. Nonetheless, as the military tide turned against the rebels in 1599–1600, he began once more to court the English. Matters were complicated by the appointment of Sir Arthur Chichester (qv), brother to John, as governor of Carrickfergus in January 1600. Chichester was a formidable soldier, made all the more so by his desire for vengeance. News of his approach in May 1600 caused James and his followers to flee in panic across the Bann. Negotiations with the English, which commenced in late 1600, progressed slowly due to mutual mistrust. With agreement close, James died under extremely suspicious circumstances on 13 April 1601. A Scottish agent, also in the pay of the English, later claimed he bribed James's surgeon to procure his death. It appears as if the English government, having judged that James and Chichester would never cooperate, decided that the simplest solution was to assassinate the former, wrongly believing that his brother and designated successor, Randal, would prove more malleable.
James married first (date unknown) Mary, daughter of Phelim O'Neill of Clandeboye; they had nine sons. In late 1597 or early 1598 he appears to have married Alice, Tyrone's daughter, who would only have been 9 or 10 years old. He was succeeded by his eldest son, Alistair Carragh, who was arrested in 1615 for complicity in a planned rising against the Ulster settlers. Later released, he was created a baronet and granted land. A younger son Sorley was obliged to flee Ireland for participating in the 1615 conspiracy, eventually finding refugee and a military command in the Spanish army in Flanders.