Alasdair Óg Mac Domhnaill
Lord of Islay
The seal of Alasdair Óg.[1] The device shows a galley manned by two men attending the ropes.[2] The seal's legend reads "S' ALEXANDRI DE ISLE".[3]
Predecessor	Aonghus Mór mac Domhnaill
Successor	Aonghus Óg Mac Domhnaill?
Died	probably 1299
Noble family	Clann Domhnaill
Spouse(s)	Juliana
Father	Aonghus Mór mac Domhnaill

Alasdair Óg Mac Domhnaill (died probably 1299) was Lord of Islay and chief of Clann Domhnaill.^{[note 1]} He was the eldest son of Aonghus Mór mac Domhnaill, Lord of Islay. Alasdair Óg seems to first appear on record in 1264, when he was held as a hostage of the Scottish Crown for his father's good behaviour. During Alasdair Óg's career, the Scottish realm endured a succession crisis as a result of the unexpected death of Margaret, Maid of Norway, heir to the Scottish throne, in 1290. One of several factions that staked a claim to the throne was the Bruce kindred. Both Alasdair Óg and his father were cosignatories of the Turnberry Band, a pact that may have partly concerned the Bruces' royal aspirations.

Aonghus Mór last appears on record in 1293, which seems to have been about the time that Alasdair Óg succeeded him as chief of Clann Domhnaill. Alasdair Óg's wife was apparently a member of Clann Dubhghaill. This marital alliance evidently brought Clann Domhnaill and Clann Dubhghaill into a territorial conflict. The chief of the latter kindred, Alasdair Mac Dubhghaill, was a close adherent to the successful claimant to the kingship, John Balliol. Following the latter's defeat and overthrow by Edward I, King of England, Alasdair Óg aligned his kindred with the English in an attempt to contend with Clann Dubhghaill. As such, Alasdair Óg was employed as the agent of English authority in the west, and Clann Domhnaill appears on record throughout the 1290s campaigning against Clann Dubhghaill, Clann Ruaidhrí, and the Comyn kindred.

Alasdair Óg's rivalry with Alasdair Mac Dubhghaill apparently brought about his own demise, as Alasdair Óg appears to be identical to the like-named man slain by Alasdair Mac Dubhghaill of Clann Dubhghaill in 1299. The Clann Domhnaill succession is uncertain following this date, as several men appear on record accorded the territorial designation "of Islay", a style that corresponded to the lordship of the Isles. Alasdair Óg is known to have had at least six sons. He was the brother of the Clann Domhnaill chief (Aonghus Óg) who was slain campaigning in Ireland in 1318. Over the succeeding decades, the Clann Domhnaill chiefship came to be permanently occupied by the descendants of Aonghus Óg. As a result, Alasdair Óg's reputation suffered within early modern Clann Domhnaill tradition, and the history of his descendants—Clann Alasdair—was largely ignored. Nevertheless, the most prominent Clann Domhnaill gallowglass families in Ireland descended from him. Members of Clann Alasdair claimed the Clann Domhnaill chiefship into the last half of the fourteenth century. Alasdair Óg may also be the eponymous ancestor of Clann Alasdair of Loup.

Alasdair Óg was an elder^[17] son of Aonghus Mór mac Domhnaill, Lord of Islay.^{[18][note 2]} The latter was a son of Domhnall mac Raghnaill,^[21] eponym of Clann Domhnaill.^[22] As such, Aonghus Mór can be regarded as the first Mac Domhnaill.^[23] Clann Domhnaill was the junior-most of three main branches of Clann Somhairle. The other two branches were Clann Dubhghaill and Clann Ruaidhrí—families respectively descended from (Domhnall's uncle) Dubhghall mac Somhairle and (Domhnall's elder brother) Ruaidhrí mac Raghnaill.^[24] Alasdair Óg had a sister who married Domhnall Óg Ó Domhnaill, King of Tír Chonaill;^[25] a younger brother, Aonghus Óg;^[26] another brother, Eóin Sprangach, ancestor of the Ardnamurchan branch of Clann Domhnaill;^[27] and a sister who married Hugh Bisset.^[28]

The personal name Alasdair is a Gaelic equivalent of Alexander.^[29] Aonghus Mór, and his Clann Somhairle kinsman Eóghan Mac Dubhghaill, evidently named their eldest sons after the kings of Scotland. Both Eóghan's son, Alasdair Mac Dubhghaill, and Alasdair Óg himself, appear to have been named after Alexander III, King of Scotland as both are unlikely to have been born during the reign of the latter's father, Alexander II, King of Scotland.^[30] Before Alexander II, virtually no Scots are known to have borne the name Alexander. Very quickly, however, leading families within the Scottish realm began to emulate the royal family.^[31] The use of the name by leading members of Clann Somhairle appears to reflect the spread of Scottish influence into its own orbit,^[32] and could be evidence of the kindred's attempt to align itself closer to the Scottish Crown.^{[33][note 3]}

In the midpoint of the thirteenth century, Alexander II, and his son and successor Alexander III, made several attempts to incorporate the Hebrides into the Scottish realm.^[36] Forming a part of the Kingdom of the Isles, these islands were a component of the far-flung Norwegian commonwealth.^[37] The independence of the Islesmen, and the lurking threat of their nominal overlord, the formidable Hákon Hákonarson, King of Norway, constituted a constant source of concern for the Scottish Crown.^[36] In 1261, Alexander III sent an embassy to Norway attempting to negotiate the purchase of the Isles from the Norwegian Crown. When mediation came to nought, Alexander III evidently orchestrated an invasion into the Isles as means to openly challenge his Norwegian counterpart's authority.^[38]

Thus provoked, Hákon assembled an enormous fleet to reassert Norwegian sovereignty along the north and west coasts of Scotland.^[39] Having rendezvoused with his vassals in the Isles—one of whom was Aonghus Mór himself—Hákon secured several castles, oversaw raids into the surrounding mainland.^[40] A series of inconclusive skirmishes upon the Ayrshire coast, coupled with ever-worsening weather, discouraged the Norwegians and convinced them to turn for home. Hákon died that December.^[41] As a result of his failure to break Scottish power, Alexander III seized the initiative the following year, and oversaw a series of invasions into the Isles and northern Scotland. Recognising this dramatic shift in royal authority, Magnús Óláfsson, King of Mann and the Isles submitted to the Scots within the year,^[42] and in so doing, symbolised the complete collapse of Norwegian sovereignty in the Isles.^[43]

In the wake of the Norwegian withdrawal, and the violent extension of Scottish royal authority into the Isles, Aonghus Mór had no choice but to submit to the Scots. He was forced to hand over his son^[44]—seemingly Alasdair Óg—who was consequently held at Ayr as a hostage of the Scottish Crown for Aonghus Mór's good behaviour.^[45] The fact that his son was accompanied by a nurse suggests that he was merely a young child at the time.^[46]

Alasdair Óg next appears on record in about 1284/1285/1286, when he confirmed his father's grant of the church of St Ciarán to the Cistercian monastery of Paisley.^[49] The witness lists of Clann Somhairle charters spanning the thirteenth century reveal that, as time wore on, the kindred increasingly surrounded itself with men drawn from a Scottish background as opposed to that of men mainly of a Hebridean milieu.^[50] In fact, Alasdair Óg's transaction with the Cistercians marks the first record of Robert Bruce VII, a future King of Scotland.^{[51][note 4]}

Other evidence of the kindred's incorporation within Scotland concerns the formation of alliances with various factions within the realm.^[54] Whilst Clann Dubhghall forged ties with the dominant Comyn kindred, Clann Domhnaill evidently aligned itself to the Bruce kindred.^[55] The latter partnership appears to owe itself to the unsettled period immediately after Alexander III's unexpected demise in March 1286. Although the leading magnates of the realm had previously recognised Alexander III's granddaughter, Margaret, as his legitimate heir, there were two major factions in the realm that possessed competing claims to the kingship. At the beginning of April, Robert Bruce V, Lord of Annandale announced his claim to the throne, whilst John Balliol—a magnate backed by the Comyns—seems to have declared a claim of his own before the end of the month.^[56]

It is possible that the Bruce faction regarded its claim to be weaker to that of Comyn-Balliol faction.^[61] In September, members of the faction concluded a pact, known as the Turnberry Band, in which certain Scottish and Anglo-Irish magnates—including Alasdair Óg and his father—pledged to support one another.^[62] One possibility is that Alasdair Óg's confirmation charter was granted immediately before or after the conclusion of the Turnberry pact. Certainly, two of the men who witnessed the grant to Paisley were members of monastery of Crossraguel, a religious house within the Bruce lordship of Carrick. This could be evidence that the charter was issued within the earldom as well.^[63] In any event, although the precise purpose of the Turnberry pact is uncertain, it is conceivable that it was somehow connected to the Bruce faction's claim to the throne.^[64] One possibility is that that involvement of Clann Domhnaill may have been intended to counter the threat of Clann Dubhghaill whilst the Bruces and their allies contended with the Balliols in Galloway.^[65]

In accordance to the pact, the participating Scottish magnates swore to support two prominent Anglo-Irish magnates: Richard de Burgh, Earl of Ulster and Thomas de Clare, Lord of Thomond.^[62] Thomas' father-in-law died the same year leaving him with claims in Connacht and Ulster.^[66] This could indicate that one of the purposes of the bond was to further the ambitions of Richard and Thomas in north-west Ireland, and enable the latter to secure possession of his northern inheritance from the clutches of his chief competitor, John fitz Thomas, and the numerous native kindreds of the region.^[67] One aspect of the pact, therefore, could have concerned the curtailment of overseas connections between Clann Domhnaill and Irish kindreds opposed to the earl, such as the Uí Domhnaill and the Uí Néill.^[68] In fact, the bond coincided with an immense show of force by Richard in Connacht and Ulster. This campaign saw the earl's exaction of hostages from Cineál Chonaill and Cineál Eoghain, the deposition of Domhnall Ó Néill from the kingship of Tír Chonaill, and the subsequent replacement of the latter with a more palatable candidate.^[69] The bond's Anglo-Irish cosignatories may have sought maritime support from Clann Domhnaill,^[70] and it is possible that Aonghus Mór contributed to the earl's operation.^[71]

Other cosignatories included members of the Stewart/Menteith kindred. The Bruces and Stewarts also had a stake in north-west Ireland, with the latter kindred eventually possessing claims to territories that had formerly been held by predecessors of John Balliol.^{[73][note 6]} The participation of the Stewart/Menteith kindred in the band could have also concerned its part in the hostile annexation of the Clann Suibhne lordship in Argyll. Forced from its Scottish homeland, Clann Suibhne evidently found a safe haven in Tír Chonaill on account of an alliance forged with Domhnall Óg.^[76] Not only was the latter's son and successor, Aodh, the product of a union with a member of Clann Suibhne,^[77] but Domhnall Óg himself had been fostered by the kindred.^[78] The fact that Murchadh Mac Suibhne is known to have died imprisoned by Richard's father could in turn indicate that the earls of Ulster were opposed to Clann Suibhne's resettlement in the region.^{[79][note 7]} Clann Domhnaill's part in Aodh's 1290 defeat at the hands of his paternal half-brother, Toirdhealbhach, meant that the forces of Clann Domhnaill were engaged supporting the cause of Aonghus Mór's maternal grandson (Toirdhealbhach) against a maternal descendant of Clann Suibhne (Aodh). Whether this clash was a direct result of the bond is uncertain, although it seems likely that Aonghus Mór's part in the pact concerned the value of his kindred's military might.^[82] Alasdair Óg may well have overseen Clann Domhnaill's overseas support of Toirdhealbhach.^{[65][note 8]}

By the death of Alexander III, the Clann Domhnaill holdings seem to have included Kintyre, Islay, southern Jura, and perhaps Colonsay and Oronsay.^[86] Whilst Aonghus Mór is regularly described with a patronymic referring to his father, Alasdair Óg and Aonghus Óg tend to be accorded the territorial designation "of Islay".^[87] In 1292, the English Crown granted Aonghus Mór and Alasdair Óg safe conduct to travel and trade between Scotland and Ireland.^[88] 1292 is also the year in which a violent feud between Clann Domhnaill and Clann Dubhghaill is first attested. The infighting appears to have stemmed from Alasdair Óg's marriage to an apparent member of Clann Dubhghaill, and seems to have concerned a dispute over this woman's territorial claims.^[89] The parentage of Alasdair Óg's wife, Juliana, is unknown. Whilst she could have been a daughter or sister of the Clann Dubhghaill chief Alasdair Mac Dubhghaill,^[90] she certainly possessed a claim to a portion of Lismore.^[91]

Image a

Image b

Facsimiles of correspondence between Clann Domhnaill and the English Crown: a letter from Aonghus Mór and Alasdair Óg (image a),^[92] and one which was attached to Alasdair Óg's seal (image b).^[93]

Although Aonghus Mór, Alasdair Óg, and Alasdair Mac Dubhghaill, swore to Edward I, King of England that they would postpone the feud, and pledged to uphold the peace in the "isles and outlying territories", the bitter internecine struggle continued throughout the 1290s.^[94] Edward directed that two of the Guardians of Scotland to be guarantors of the peace. One was the steward, whilst the other was John Comyn II, Lord of Badenoch. The fact that the latter was a brother-in-law of Alasdair Mac Dubhghaill could indicate that the steward and Clann Domhnaill were politically aligned.^[95]

In February 1293, at the first parliament of John, King of Scotland, three new sheriffdoms were erected in the western reaches of the realm.^[96] In the north-west, William II, Earl of Ross was made Sheriff of Skye, with a jurisdiction that appears to correspond to the territories formerly held by the Crovan dynasty before 1266. In the central-west, Alasdair Mac Dubhghaill was made Sheriff of Lorn, with a jurisdiction over much of Argyll. In the south-west, the steward was made Sheriff of Kintyre.^[97] The creation of these divisions dramatically evidences the steady consolidation of royal authority in the west in since 1266.^{[98][note 9]} Despite the king's intentions of increased authority, stability, and peace, his new sheriffs seem to have used their elevated positions to exploit royal power against their own local rivals. Whereas Clann Ruaidhrí appears to have fallen afoul of the neighbouring Earl of Ross, Clann Domhnaill was forced to deal with its powerful Clann Dubhghaill rivals.^[104]

Aonghus Mór is last attested in 1293,^[106] and appears to have died at about this date.^{[107][note 10]} Alasdair Óg's undated renewal of his father's grant of St Ciarán seems to be evidence that Aonghus Mór had been succeeded by the date of its issue.^[109] Certainly, Alasdair Óg appears to have succeeded Aonghus Mór by the mid 1290s.^[110] The record of Alasdair Óg serving as a young hostage in 1264 suggests that he would have been in his thirties at the time of his succession.^[111]

In an effort to curb the principal representative of the Comyn-Balliol faction in the north-west, Alasdair Mac Dubhghaill, Edward turned to Alasdair Óg.^[112] The latter was evidently serving the English Crown by March,^[113] and is attested in April as an English-aligned bailiff in Kintyre, tasked to seize control of Kintyre and hand it over to a certain Malcolm le fitz l'Engleys.^[114] As such, Alasdair Óg was given jurisdiction over an area formerly under the authority of the steward,^[115] a man who had briefly taken up arms against the English in 1296 but quickly capitulated when resistance proved futile.^[116]

By 10 September, however, Edward turned to Alexander Stewart, Earl of Menteith, who was appointed authority over an expansive territory stretching from Ross to Rutherglen. The earl was ordered to take into custody the property of Alasdair Mac Dubhghaill and Eóin Mac Dubhghaill;^[117] his was given authority over specific magnates such as the steward, (the keeper of Ross) William Hay, John Comyn II, and Niall Caimbéal; as well as the burghs of Ayr, Renfrew, Dumbarton; and given authority over the men of Argyll and Ross.^[118] It is unknown what prompted the king to turn towards the earl. The latter had been captured following the Scottish defeat at Dunbar in April,^[119] and had been released from custody in June.^[120] One possibility is that the English Crown sought to rely upon a power that was less personally involved in the politics of the region. It is also possible that the English orchestrated this delegation of authority in the context of adopting a divide-and-rule policy in the region as a way to offset Alasdair Óg's influence.^[121]

In an undated letter that appears to date to about the summer of 1296, Alasdair Óg reported to the English king that he had secured possession of the steward's lands in Kintyre, and was on verge of taking control of a particular castle.^[123] Although this fortress is unnamed, it may have been either Dunaverty Castle^[124] of Skipness Castle^[125]—either of which could have been the steward's principal stronghold in Kintyre.^[122] Alasdair Óg also advanced the opinion that, under the Scottish and English law, no tenant-in-chief should lose his heritage without first being impleaded by writ in their name.^[123] However, the fact that Malcolm is on record in possession of Dunaverty Castle a decade later suggests that Alasdair Óg's letter was an insincere—and unsuccessful—attempt to prevent Malcolm from gaining a foothold in Kintyre.^[126] By early May, the steward duly submitted to the English Crown.^[127] Whether Alasdair Óg was aware of the steward's submition is unknown. As a result, his castle could have been seized by Alasdair Óg or merely handed over to him.^[128] In September 1296, Edward ordered that Alasdair Óg be granted £100 of lands and rent for his services to the English Crown.^[129]

It is evident that, from about 1296 to 1301, Clann Dubhghaill was out of favour of the English Crown. The efforts of Edward's adherents in Argyll were evidently successful since the next record of Alasdair Mac Dubhghaill reveals that the latter had been imprisoned at some point^[135]—presumably in an attempt to pacify his family^[136]—and was released by Edward in May 1297.^{[137][note 12]} With the Clann Dubhghaill chief's liberation, Edward may have hoped to reign in his disaffected son, Donnchadh,^[140] a man who—unlike his father—had not sworn allegiance to the English Crown,^[141] and who was evidently spearheading his family's resistance to Clann Domhnaill.^[142]

The struggle between Clann Domhnaill and Clann Dubhghaill is documented in two undated letters from Alasdair Óg to Edward. In the first, Alasdair Óg complained to the king that Alasdair Mac Dubhghaill had ravaged his lands. Although Alasdair Óg further noted that he had overcome Ruaidhrí Mac Ruaidhrí and thereby brought him to heel,^[143] the fealty that Ruaidhrí swore to the English Crown appears to have been rendered merely as a stalling tactic,^[144] since the letter reveals that Ruaidhrí's brother, Lachlann Mac Ruaidhrí, then attacked Alasdair Óg, and both of these Clann Ruaidhrí brothers proceeded to ravage Skye and Lewis and Harris. At the end of the letter, Alasdair Óg related that he was in the midst of organising a retaliatory operation, and implored upon Edward to instruct the other noblemen of Argyll and Ross to aid him in his struggle against the king's enemies.^[143] In a writ dated 9 April 1297, Edward ordered that the men of Argyll and Ross assist Alasdair Óg, who was thereby appointed as the king's bailiff in Lorn, Ross, and the Hebrides.^[145] As such, Alasdair Óg was granted authority in Alasdair Mac Dubhghaill's former sheriffdom.^[146] If the royal command was a response to Alasdair Óg's letter, as seems the case, it would suggest that he composed his correspondence to the king in the midpart of March.^[147]

In the second letter, Alasdair Óg again appealed to the English Crown, complaining that he faced a united front from Donnchadh, Lachlann, Ruaidhrí, and the Comyns. According to Alasdair Óg, the men of Lochaber had sworn allegiance to Lachlann and Donnchadh. In one instance Alasdair Óg reported that, although he had been able to force Lachlann's supposed submission, he was thereupon attacked by Ruaidhrí. Alasdair Óg further related a specific expedition in which he pursued his opponents to the Comyn stronghold of Inverlochy Castle^[148]—the principal fortress in Lochaber^[149]—where he was unable to capture—but nevertheless destroyed—two massive galleys which he described as the largest warships in the Western Isles.^{[148][note 13]} Alasdair Óg also reported that, on account of the steward's disloyalty to the king, he seized control of the castle and barony of "Glasrog" (probably Glassary).^[148] There is only one other reference to a castle in the barony of Glassary—presumably Fincharn Castle—in 1374.^[152] How the steward came to hold any authority in these Argyllian lands is uncertain. One possibility is that he capitalised upon the conflict between Clann Domhnaill and Clann Dubhghaill.^[153] In any event, much like in the first letter, Alasdair Óg called upon the English king for financial support in combating his mounting opponents. Specifically, he reminded the English Crown that he had received nothing of the £500 that he had been promised the year before, nor had he received any revenue from his duties as bailiff.^[148]

Alasdair Óg's dispatches seem to show that Lachlann and Ruaidhrí were focused upon seizing control of Skye and Lewis and Harris from the absentee Earl of Ross. Whilst the first communiqué reveals that the initial assault upon the islands concerned pillage, the second letter appears to indicate that the islands were subjected to further invasions by Clann Ruaidhrí, suggesting that the acquisition of these islands was the family's goal. The bitter strife between Clann Ruaidhrí and Clann Domhnaill depicted by these letters seems to indicate that both kindreds sought to capitalise on the earl's absence, and that both families sought to incorporate the islands into their own lordships. In specific regard to Clann Ruaidhrí, it is likely this kindred's campaigning was an extension of the conflict originating from the creation of the shrievalty of Skye.^[156] The correspondence also reveals that the Lachlann and Ruaidhrí were able to split their forces and operate somewhat independently of each other. Although Alasdair Óg was evidently able to overcome one of the brothers at a time, he was nevertheless vulnerable to a counterattack from the other.^[157]

Alasdair Óg's second letter appears to date to after his reception of the king's writ of 9 April.^[158] Whether the Clann Somhairle kin-strife continued after Alasdair Mac Dubhghaill's May release is uncertain, although it would seem highly probable given the remarkable animosity between the concerned parties.^[159] If Edward did not intend for this liberated clan chief to reign in his family, another possibility is that his release was instead envisaged as a counterbalance to Alasdair Óg's power, to ensure that the latter was kept in check.^[160] The correspondence between Alasdair Óg and the English also reveals that, notwithstanding Edward's 1296 grant of administrative powers to Alexander Stewart in the northwest, it was actually Alasdair Óg who was implementing English royal authority in the region.^[161] Nevertheless, although Alasdair Óg was ostensibly working on the king's behalf, it is evident that local rivalries and self-interest laid behind the region's political alignments, not anti-Englishness.^{[162][note 15]} Certainly, the English Crown's elevation of Alasdair Óg at the expense of the steward and Clann Dubhghaill would have been a cause of apprehension and resentment.^[165] In fact, it is apparent that little authority could be expected by Edward without bringing these two disaffected parties onside.^[166]

In 1299, several Irish annals report a clash between Clann Domhnaill and Clann Dubhghaill in which Alasdair Mac Dubhghaill slew a member of Clann Domhnaill named Alasdair.^{[168][note 16]} According to the seventeenth-century Annals of the Four Masters, this man was "the best man of his tribe in Ireland and Scotland for hospitality and prowess"; whilst the fifteenth- to sixteenth-century Annals of Ulster states that he was killed "together with a countless number of his own people ... around him".^[173] The slain man appears to have been Alasdair Óg himself.^[174] The accounts of his demise suggest that his final fall took place in the context of his ongoing dispute with Clann Dubhghaill.^[175]

[Note: According to the annals of Clan Donald, Alasdair Og (Alexander of Islay) was fighting against Robert the Bruce in 1308 in Galloway where he was defeated on the banks of the Dee by Edward, brother of King Robert the Bruce. Edward took prisoner "the prince of the Isles" but Alexander escaped to Castle Sween in Knapdale. Edward pursued him and captured Alexander there. He was taken to Dundonald Castle in Ayrshire where he was held prisoner and died soon after.]^[176] But this is widely disputed.

If the seventeenth-century Ane Accompt of the Genealogie of the Campbells is to be believed, Clann Dubhghaill successfully dispatched another rival during the 1290s, as this source claims that Eóin Mac Dubhghaill overcame and slew Cailéan Mór Caimbéal.^[177] The latter's death took place after his recognition as bailiff of Loch Awe and Ardscotnish by Edward in September 1296, suggesting that he too was employed by the English against Clann Dubhghaill.^{[178][note 17]} Accordingly, both Alasdair Óg and Cailéan Mór appear to have succumbed to Clann Dubhghaill whilst attempting to extend Edward's authority into Argyll and bring the clan to heel.^{[180][note 18]}

Alasdair Óg's death in 1299 seems to account for the recorded actions of his younger brother, Aonghus Óg, against Clann Dubhghaill.^{[175][note 20]} In either 1301 or 1310 for example, whilst in the service of the English Crown, Aonghus Óg inquired of the king as to whether he and Hugh were authorised to conduct military operations against Alasdair Mac Dubhghaill, and further entreated the king on behalf of Lachlann and Ruaidhrí—who were then aiding Aonghus Óg's English-aligned military forces—to grant the Clann Ruaidhrí brothers feu of their ancestral lands.^[187] Another letter—this one from Hugh to Edward—reveals that Hugh, Eóin Mac Suibhne, and Aonghus Óg himself, were engaged in maritime operations against Clann Dubhghaill that year.^{[188][note 21]}

The fact that Aonghus Óg styled himself "of Islay" in his letter could be evidence that he was acting as chief of Clann Domhnaill,^[175] and that he succeeded Alasdair Óg as chief.^[190] Nevertheless, the precise succession of Clann Domhnaill is uncertain. For example, the record of a certain Domhnall in attendance of the 1309 parliament of Robert I, with the territorial designation "of Islay", could indicate that this particular man then held the chiefship.^[191] As with the succession, the identity of this man is uncertain. One possibility is that he was an elder brother of Aonghus Óg;^[192] other possibilities are that he was either a cousin of Alasdair Óg and Aonghus Óg,^[193] or else a son of either two.^{[194][note 22]}

Further evidence of a contentious family succession may be the record of a certain Alasdair of the Isles,^[199] who received a grant of the former Clann Dubhghaill islands of Mull and Tiree from Robert I.^[200] This man could have been a son of Aonghus Óg,^[201] or else a nephew of the latter^[202]—presumably a son of Alasdair Óg himself.^[203] Certainly, Alasdair of the Isles's royal grant comprised former Clann Dubhghaill islands, a fact which could be evidence that he was indeed a son of Alasdair Óg, and possessed a claim to these territories by right of his maternal descent from Clann Dubhghaill.^{[204][note 23]} Remarkably, this is no evidence of a royal charter to the lordship of Islay. This could reveal that, upon Alasdair Óg's death, the lordship was automatically inherited by a son, possibly Alasdair of the Isles.^[206] The latter may be identical to the apparent Clann Domhnaill chief slain in 1318 supporting the Bruce campaign in Ireland.^[204] The sixteenth-century Annals of Loch Cé records his name as "Mac Domnaill, ri Oirir Gaidheal".^[207] This source is mirrored by several other Irish annals,^{[208][note 24]} and the eleventh- to fourteenth-century Annals of Inisfallen seems to refer to the same man, calling him "Alexander M" in an only partially-decipherable entry.^[213] The albeit exaggerated title "King of Argyll" accorded to this slain Clann Domhnaill dynast appears to exemplify the catastrophic effect that the rise of the Bruce regime had on its opponents like Clann Dubhghaill.^[214] Until its downfall in 1309, Clann Dubhghaill was closely associated with the lordship of Argyll.^[215] In consequence, this Argyllian title could be evidence that a son of Alasdair Óg possessed the inheritance of both Clann Domhnaill and Clann Dubhghaill.^[204]

Alasdair Óg is the eponymous ancestor of the Clann Alasdair branch of Clann Domhnaill.^{[217][note 25]} Surviving genealogical sources reveal that he had at least six sons:^[222] Eóin Dubh, Raghnall, Toirdhealbhach, Aonghus, Gofraidh, and Somhairle.^[223] Following his death, Alasdair Óg's sons evidently established themselves as gallowglass commanders in Ireland.^[224] In fact, three are recorded as commanders in contemporary Irish annalistic sources, and all founded prominent Irish gallowglass families.^[223] As such, Alasdair Óg's descendants formed the major gallowglass families of Clann Domhnaill.^{[225][note 26]} The first to be recorded in such a capacity is Eóin Dubh, a man whose violent demise is reported in 1349.^[229]

Other than Alasdair of the Isles, another possible son of Alasdair Óg is Ruaidhrí of Islay,^[233] a man who suffered the forfeiture of his possessions by Robert I in 1325.^[234] The parentage of this man is uncertain, and it is conceivable that was a member of either Clann Ruaidhrí^[235] or Clann Domhnaill.^[236] The downfall of Alasdair Óg's lineage in the Clann Domhnaill heartland seems to account for the kindred's relocation to Ireland as mercenary commanders.^[5] If Ruaidhrí of Islay was indeed a member of Clann Domhnaill, and a son of Alasdair Óg, his expulsion may have marked the downfall of Clann Alasdair in Scotland, and may account for the fact that Alasdair Óg's descendants failed to hold power in Hebrides after this date. As such, Ruaidhrí of Islay's expulsion could well mark the date upon which Clann Alasdair relocated overseas.^[237] Another family descended from Alasdair Óg is probably Clann Alasdair of Loup in Kintyre.^{[238][note 27]}

The eclipse of Alasdair Óg's line—the senior branch of Clann Domhnaill—may explain the rise of Aonghus Óg's line. If Ruaidhrí of Islay indeed represented the line of Alasdair Óg by 1325, his forfeiture evidently paved the way for the rise of Aonghus Óg's son, Eóin.^[241] In fact, before the end of Robert I's reign, this Eóin appears to have administered Islay on behalf of the Scottish Crown,^[242] and eventually came to style himself Lord of the Isles.^[243]

Some of the accounts of Alasdair Óg, preserved by seventeenth-century Sleat History, have little in common with the man recorded by other, more contemporary and perhaps more accurate accounts.^[246][247] For example, according to the Sleat History, Alasdair Óg was "always" an enemy of Robert I, and consistently fought alongside Eóin Mac Dubhghaill against this king. At one point, Alasdair Óg is said to have been besieged by the king within Castle Sween, where he was captured and later died there as a prisoner, however, the better reasoned view is that he was always loyal to the Bruces. His younger brother, Aonghus Óg, likewise always supported Robert I in "all his wars".^{[248][note 28]} This skewed view of Alasdair Óg seems to have been constructed as a means to glorify the branch of Clann Domhnaill descended from Aonghus Mor's younger brother Alasdair Mor at the expense of Alasdair Óg and his reputation. As such, the history of the Clann Alasdair branch of the clan is ignored by the Sleat History.^[250]