O'Doherty (Ó Dochartaigh), Cahir (1587–1608), lord of Inishowen, was born in Co. Donegal, the eldest son of Seán Óg O'Doherty, lord of Inishowen (1582–1601), and grandson of Seán O'Doherty, lord of Inishowen (d. 1582). He had two younger brothers, Seán and Rury, and a half-brother, Donnell, as well as two known sisters, Rosa (qv) and Margaret. Little is known of his early life. He was sometimes called Cahir Rua and was certainly fostered by the McDaid family, who were the most influential sub-chieftains in Inishowen. During his childhood the most prominent McDaids were the four brothers Hugh Boy, Phelim Reagh, Eamonn Gruam, and Shane Cron. Hugh Boy in particular is singled out in sources as Cahir's foster-father, although he left Ireland in 1584 to serve in Sir William Stanley's (qv) regiment in the Spanish service in the Netherlands and did not return until 1595. It is likely that, as a result, Phelim Reagh McDaid had responsibility for the boy's early upbringing.
Inishowen was one of the largest sub-lordships in the lordship of Tír Conaill, and Cahir's father was one of the most prominent nobles in the time of the chieftains Aodh mac Maghnusa O'Donnell (qv) and Red Hugh O'Donnell (qv). The Annals of the Four Masters state of Seán Óg O'Doherty that ‘there was not among all the Irish of his time a lord of a triocha-ched of better hand or hospitality, or of firmer counsel, than he’, while of his grandfather they say that he was ‘a person for whose ransom (if he could have been ransomed) many horses and herds would have been given’. Seán Óg was imprisoned by Lord Deputy Fitzwilliam (qv) in 1588 in an effort to extort treasure the lord deputy assumed he had obtained from survivors from the Spanish Armada. Seán Óg, although one of the last nobles in Tír Conaill to submit to Red Hugh O'Donnell, was one of the latter's most important commanders throughout the Nine Years’ War. He commanded many raids for him, provided his overlord with finance on occasion, and killed the English officer Sir John Chamberlain near Derry in 1600. He died 27 January 1601.
Cahir O'Doherty first came to prominence in May 1600, when Sir Henry Docwra's (qv) English force landed at and fortified Derry and Culmore on the borders of Inishowen. Red Hugh O'Donnell took O'Doherty as pledge for the continued loyalty of his father, in whom he put great trust, leaving him to watch Docwra's force in June 1600 when he himself marched south to plunder Clanrickard and Thomond. However, the people of Inishowen became the first element of the population of Tír Conaill to suffer heavily in the Nine Years’ War when in December 1600 English soldiers got onto Inch Island in Lough Swilly and massacred 150 of O'Doherty's followers.
Following his father's death in January 1601 O'Doherty assumed a central role in Tír Conaill politics. Because of a bribe of 1,200 cattle Red Hugh inaugurated O'Doherty's uncle Phelim Óg O'Doherty as lord of Inishowen. This act outraged Cahir's foster family, the McDaids. Sir Henry Docwra later stated that ‘These men took it as the highest injury [that] could be done unto them, that their foster child should be deprived of that, which they thought was his clear and undoubtable right’ (O'Donovan, 248). As a result the McDaids, led by Hugh Boy, opened up negotiations with Docwra in Derry. Articles of agreement were drawn up in February 1601. Docwra promised ‘that he will presently set up and proclaim the said Cahir O'Doherty as lord of the country of Inishowen under the Queen’, although O'Doherty was still very young, only fourteen. The Annals of the Four Masters state Docwra did this ‘to spite O'Donnell’. For some unknown reason Hugh Boy managed to secure Cahir's release from Red Hugh O'Donnell, and when the young O'Doherty returned to his followers they quickly joined the English. War broke out with the forces of Red Hugh, and in May 1601 the O'Dohertys and McDaids assisted the English in thwarting an invasion of Inishowen by O'Donnell's army.
In 1602, after Red Hugh O'Donnell had marched south to be defeated at Kinsale, O'Doherty campaigned with Docwra in Tyrone. In one skirmish near Omagh he conducted himself well and was recommended for a knighthood by Sir Henry; he was subsequently knighted by Lord Deputy Mountjoy (qv). However, a force of 100 kerne, whom he sent to join the English thrust into Glanconkeine, mutinied and refused to enter the wooded defile. He was also deprived of a level-headed adviser at this time when Hugh Boy McDaid was killed in August 1602.
After the war O'Doherty's lordship was separated from the rest of Tír Conaill, which was granted to the first earl of Tír Conaill, Red Hugh's brother Ruaidhrí O'Donnell (qv). However, it was still included in Co. Donegal. O'Doherty's sister Rosa married Ruaidhrí's brother Caffar and he himself married Mary Preston, the daughter of the fourth Viscount Gormanston, with whom he had a daughter. He visited court at London in 1603 and on 4 September was granted his patent for Inishowen. This grant included ‘The manors, lordships, castles (except the castle of Culmore, with 300 acres of land adjoining, and the fishing thereof), messuages, lands, presentations, advowsons, and all other hereditaments whatever . . . in the country called Inishowen’. While Sir Henry Docwra remained in Derry, O'Doherty had a friendly neighbour: he was created a JP and an alderman of the city. However, signs began to emerge that he did not understand the role he was expected to play in Jacobean Ulster. Inch Island in Lough Swilly, a part of the lordship of Inishowen, was granted to Sir Ralph Bingley (qv). O'Doherty appealed to Docwra to return the island to him and could not comprehend the situation when Docwra felt unable to overturn a grant made under the great seal.
In July 1606 Sir Henry was replaced as governor of Derry by Sir George Paulet (qv), a man who did not have much patience for the Gaelic Irish of the area. O'Doherty's cause was not helped in September 1607 when his sister Rosa O'Doherty participated in the flight of the earls. In November 1607 he was accused of attempting to fortify Tory Island in a treasonable plot (in actual fact he had sailed to the forest of Ceann Maghair in Fanad to obtain wood to repair one of his castles). O'Doherty was very upset by the allegations and wrote to Paulet that ‘you hold a very hard opinion of me’. He then travelled to Dublin to press his case before the lord deputy, Sir Arthur Chichester (qv). However, he was imprisoned for a short period and only released after being bound to a recognisance of £1,000 and two sureties of 500 marks (November 1607). Nevertheless, in 1608 he was appointed foreman to the jury which indicted the northern earls for their flight, along with the other notables of Tír Conaill. O'Doherty also at this time lobbied to be appointed to the household of the prince of Wales at court – an appointment that would have ensured his future. Indeed, in April 1608 the English privy council decided to return Inch Island to him.
However, in the same month, in Derry, O'Doherty fell out with Governor Paulet. The Annals of the Four Masters state that Paulet actually struck him physically – ‘inflicted chastisement on his body’ – an action that outraged the young O'Doherty and his followers. O'Doherty seems to have been advised at this time principally by Phelim Reagh McDaid, and his plight was exploited by Niall Garvach O'Donnell (qv) for his own advantage. O'Doherty and his followers decided in the heat of the moment to take Derry and launch a rebellion. Although clever stratagems were thought up, there seems to have been no wider plan, as he had very few allies or arms, and really no hope of success. Here the loss of Hugh Boy McDaid in 1602 was keenly felt.
O'Doherty seized Captain Hart, the commander of Culmore Fort, after inviting him to dinner and, having lured the garrison out on the night of 18 April, captured the fort and its munitions. Derry was stormed at two o'clock the next morning, when Governor Paulet, under-sheriff Harris, and a small number of other English were slain. Susan Montgomery, the wife of the bishop of Derry, was captured and Phelim Reagh McDaid then set fire to the town. O'Doherty and his allies later seized Tory and Aran islands and based themselves in the mountain fastness of Glenveagh.
The English administration led by Lord Deputy Chichester took decisive action against O'Doherty's revolt. Columns were sent north from the east and the south, and Derry was recaptured on 20 May. A price of 500 cattle was put on O'Doherty's head, ‘dead or alive’, and 200 on that of Phelim Reagh McDaid. O'Doherty's main stronghold, Burt Castle, was surrendered by his wife, who does not seem to have supported his rebellion, following a very short bombardment. O'Doherty, in a letter in Irish to the chieftain of the O'Gallaghers, wrote: ‘Let no man imagine that we are anything the weaker for loosing Burt Castle, unless he may take thought for the unconstantness of such as he trusted of his own people, whom now he little regards’ (SP 63/224/181). At its peak his following reached 1,000 men, but outside of northern Tír Conaill the only other area to support him was south Armagh, led by his brother-in-law Eochaidh O'Hanlon (qv). The English campaign force sent against him numbered 800 men backed by 500 Irish auxiliaries. O'Doherty raided into Tyrone, burnt Armagh town, and killed Henry Óg O'Neill at Kinard. When he returned to Tír Conaill the English attempted to trap him in Glenveagh but he managed to escape. However, when he gave battle against an English force near the rock of Doon at Kilmacrennan, he was shot in the head by an English soldier and killed on 5 July 1608 (on 8 July 1608, according to the Four Masters). He was only twenty-one years of age. His men dispersed. The survivors of the defeat at Kilmacrennan were soon routed out of the islands off western Tír Conaill, although rebel elements survived in Armagh until transported to Sweden in 1609. Phelim Reagh McDaid disbanded his few remaining supporters in July 1608 and attempted to escape to the highlands of Scotland, but was captured. He was executed along with twenty others at Lifford in September 1608.
O'Doherty's revolt had very wide ramifications. As immediate effects he himself and his principal adviser, Phelim Reagh McDaid, were killed and Inishowen and most of northern Tír Conaill plundered by English forces. More importantly, the province of Ulster was now wide open to plantation, which occurred in 1610. In that year, as part of the new settlement, Lord Deputy Chichester was granted the entire lordship of Inishowen. Most of O'Doherty's allies were killed; all were dispossessed. Niall Garvach O'Donnell, who encouraged and then abandoned him, was imprisoned for life in the Tower of London. Of O'Doherty's own family, his wife appears to have regretted her marriage and his daughter may have died in infancy. His brother Rury fled to the Spanish Netherlands, while his other brother, Seán, died in 1638. The most prominent member of his family was his sister Rosa, who later married General Owen Roe O'Neill (qv).