O'Connor Sligo, Sir Donal (Domhnall) (d. 1588), lord of the O'Connor Sligo, was the second son of Tadhg, lord of the O'Connor Sligo. After Tadhg's death in 1552, Rory Mac Phelim O'Connor Sligo became the new lord, but Donal disputed the succession and a bitter civil war erupted. Rory prevailed, but Donal succeeded him c.1561. He ruled a beleaguered lordship, menaced by the O'Rourkes from the east, the Burkes from the south, and, particularly, the O'Donnells from the north. The O'Donnells had long claimed overlordship of the O'Connor Sligo's lands and levied a tribute on the area.
The arrival in the north-west in autumn 1566 of a royal army commanded by the lord deputy of Ireland, Sir Henry Sidney (qv), opened up new opportunities for Donal. On 24 October he signed a preliminary agreement with Sidney at Boyle abbey, Co. Roscommon, whereby Donal recognised Elizabeth as his monarch. He told Sidney that he wished to hold his lands directly of the queen and to be free from O'Donnell. He was knighted by Sidney on 4 April 1567 at Loughrea, and was one of a number of Gaelic lords who accompanied Sidney to London later that year. On 20 January 1568 he formally submitted to the queen, agreeing to surrender his Irish title and to hold his estates by English letters patent in return for an annual rent not exceeding £100. He expected the crown to uphold his independence from Aodh O'Donnell (qv), but on returning home that spring he found that the Dublin administration lacked both the means and the inclination to do so. Remaining firmly under O'Donnell's thumb, Donal neither took out his letters patent nor paid his annual rent.
The situation began to change from 1575, when the crown expanded into north Connacht. In summer 1576 Donal met with Sidney in Dublin and renewed the agreement to pay a yearly rent of £100 in return for protection from O'Donnell. In 1577 Donal and his close ally Brian MacDermot of Moylurg met with the royal governor of Connacht, Sir Nicholas Malby (qv), in Roscommon to request aid against O'Donnell. With English reinforcements, Donal and McDermot took Bundrewes castle on the southern border of Tyrconnell. O'Donnell responded that autumn with a devastating raid on Sligo, before besieging Bundrewes castle; Malby's forces arrived soon afterwards and lifted the siege. Although Donal's ambitions appeared finally to have been fulfilled, disappointment followed. Malby said that the rent agreed previously was inadequate, and attempted to pressure Donal into signing a new, significantly harsher indenture. As the crown then sought good relations with O'Donnell, Malby had no reason to contest O'Donnell's pretensions to overlordship of Sligo. Donal refused to sign a new indenture or to pay any royal rent, saying he could not be expected to pay a tribute to O'Donnell and to the queen. An unsympathetic Malby quartered troops on Donal's lands, briefly seized Ballymote castle, and then in 1578 wrested Bundrewes castle from Donal before selling it to O'Donnell. In early 1580 Donal came to an informal arrangement with Malby, agreeing to make regular payments for the upkeep of royal forces in Connacht, after which relations between the two improved. That summer O'Donnell suffered military defeat at the hands of Turlough Luineach O'Neill (qv) and henceforth was too weak to assert his claim over Sligo, thereby removing the main bone of contention between Malby and Donal.
The early 1580s was a period of unrest in north Connacht, with many Scottish mercenaries entering the province from Ulster to participate in the fighting. Sligo was the gateway into Connacht and Donal's lands were repeatedly subjected to rebel raids. Nonetheless, he remained firmly loyalist. In March 1581 his older brother and close ally, Cathal Óg, was killed in fighting with Scots. That autumn Malby hired these same mercenaries and quartered them on Donal's lands. Apparently with Malby's consent and with the assistance of some English officers, Donal and his supporters attacked the Scots, killing many of them, including those who had slain his brother.
Malby's death in 1584 and the appointment of Richard Bingham (qv) to succeed him as governor of Connacht disrupted Donal's relationship with the authorities. Bingham quickly earned a reputation for great harshness and, wishing to establish his own private colony in Sligo, seized Ballymote castle in Donal's lordship. However, Donal shrewdly exploited the rivalry between Bingham and the lord deputy, Sir John Perrot (qv), whom he met in Dublin. On 22 December 1584 he signed an indenture with Perrot whereby a crown rent and cess was formally imposed on his lands and Ballymote and its environs were reserved to the crown. In return, his authority throughout all of Co. Sligo was recognised and for the first time he received letters patent for his lands, providing him with legal protection from Bingham's predatory designs. He received a further boost in 1585 under the terms of the composition of Connacht: he was exempted from paying the composition and became the only lord in Sligo entitled to rents from his vassals in commutation of his traditional taxes in kind. Better still, the crown now firmly opposed O'Donnell's claims in Sligo. Attempts by Bingham to undermine the composition by provoking Donal and his supporters during 1585–6 were thwarted by Perrot who proved an effective patron.
Finally secure, Donal O'Connor Sligo spent his last years developing his lands and built a bridge at Ballysadare. He died 6 January 1588 at Sligo town and was buried at Sligo abbey. He married Mor O'Rourke, with whom he had a son, Calvagh, who died in 1581, and at least one daughter, Maeve, who married Brian MacDermot of Moylurg.
Donal's nephew, Sir Donough (Donchadh) O'Connor Sligo (d. 1609), lord of O'Connor Sligo, was the son of Cathal Óg, eldest brother of Sir Donal. Under the terms of Donal's 1584 indenture with the government, Donough should have succeeded to his uncle's estate. However, in February 1588 Bingham blocked the succession, claiming that Donough's father was illegitimate and that the estate fell to the crown. Perrot established a commission to determine the issue, which found in Donough's favour in March 1588. Only after being ordered to do so three times by Perrot, did Bingham allow Donough to enter into possession of his lands in late May. However, the panic caused by the appearance of the Spanish armada off the coast of England that summer allowed Bingham to press his case again. He won over the queen by arguing that the strategic importance of Sligo demanded that it be placed in English hands. In August another commission established by Bingham found Donough's father to be illegitimate and dispossessed him. Bingham determined that the crown should retain Sligo castle and the barony of Carbury (the heart of the O'Connor Sligo lordship) and that Donough should be granted the rest of the O'Connor Sligo lands as a gift from the queen, but not as his inheritance.
In September 1588 Donough went to London to petition for redress and to complain that Bingham had coerced jurors into finding against him. However, his pleas were disregarded, Bingham accused him of conspiring against the government and he was detained indefinitely in London, where he ran up massive debts. Meanwhile, Bingham was granted custody of the O'Connor Sligo estate, which he ran as his own personal fiefdom, while the notorious land grabber William Taaffe (qv) underhandedly procured royal grants of much of Donough's estate. Donough's prospects improved in 1596 when the success of the rebel leader Red Hugh O'Donnell (qv) in overrunning much of north Connacht, including Sligo, led to Bingham's recall.
In March 1596 the queen granted Donough permission to return to Ireland, granted him all his lands except Carbury, and made him constable of Sligo. He returned to Sligo in August where his clan rallied behind him against O'Donnell and where he persuaded O'Connor Roe and his brother-in-law Theobald Bourke (qv) (Tibbet-na-Long) to submit to the crown. However, O'Donnell quickly tempered this loyalist enthusiasm by launching a devastating raid on Sligo that targeted only Donough's supporters. In February 1597 there was heavy fighting between Donough and O'Donnell; in March, he helped the governor of Connacht, Conyers Clifford (qv), to capture Sligo castle and was installed there as head of a garrison. That summer he participated in Clifford's campaign in Tyrconnell, where he was wounded in the unsuccessful siege of Ballyshannon. Clifford and others praised Donough for his efforts but even with English help he struggled to maintain himself in Sligo against the formidable O'Donnell.
In February 1598 Donough went to London to petition for Ballymote castle; his plea was unavailing. During his absence, rebels took Sligo castle and Ballymote. On returning to Ireland in the summer, Donough was effectively shut out of Sligo and instead went for a time to Munster, where his wife, Eleanor Butler (qv), dowager countess of Desmond, held land. About June 1599 he returned to Sligo to spy on O'Donnell, establishing himself at Collooney castle, the only fort he had left. O'Donnell became aware of his presence and besieged his stronghold, preventing any escape. The government dispatched a relieving army under Clifford, but O'Donnell's men routed this force at the battle of Curlew Mountains on 5 August. Donough surrendered on being presented with Clifford's severed head.
He was forced to hand over hostages to O'Donnell and to promise his support for the rebellion. O'Donnell resettled him in his lordship and he served under O'Donnell against royal forces in 1600–01. Nonetheless, he remained in contact with the government, claiming that his true loyalty was to the queen. In July 1601 O'Donnell discovered that Donough was plotting to betray him and imprisoned him in irons on an island in Lough Esk. During this period of captivity, he contemplated suicide but held back out of fear for his soul.
About July 1602 Ruaidhrí O'Donnell (qv), brother to Red Hugh, freed Donough in return for his promise of support against the English. For the next three months Ruaidhrí and Donough fought with crown forces in Sligo, winning a significant victory over 400 government troops at the Curlew Mountains in August. However, the rebels’ position was desperate and the two leaders surrendered on terms in December. In recognition of his previous loyalty and of the price he had paid for it, Donough was pardoned and knighted in 1604. Finding that Taaffe held the title to much of his estate, Donough was forced to mortgage his remaining lands heavily in order to buy him out. Thereafter, he was preoccupied with defending his estate in a series of legal cases from opportunists seeking to exploit flaws in his title to the lands. The loss of Ballymote castle aside, he was successful, but the cost of these numerous legal defences worsened his already parlous finances. He died suddenly in August 1609 and was buried at Sligo abbey, where in 1624 his widow erected an impressive tomb for him, built in the renaissance style, which still survives. He had no children and was succeeded by his brother Donal.