WI: Vikings slaughtered at Dumbarton Rock, 870 CE

[cincpac overboard]

In 870 CE the stronghold of Alt Clut (now Dumbarton Rock) fell after a four month siege to a Viking army from Dublin, led by Amlaib and Imar, the ruler of Dublin and his brother, respectively. Alt Clut was the center of a small but wealthy Brittonic kingdom and controlled access to the lowlands of what is now Scotland. Possible maritime competition with Dublin may have played a part in motivating the siege, in addition to the prospect of loot. According to Irish chronicles, the Vikings returned to Dublin with a fleet of 200 ships, carrying not only captive Britons but also Angles and Picts captured in earlier raids.

Suppose instead that somehow Alt Clut was sufficiently forewarned of the coming attack and managed to annihilate the Viking force, capturing or killing Amlaib and Imar in the process. This severely weakens Dublin, the most powerful Viking settlement in Ireland, who might then be attacked by native Irish kingdoms that had suffered from frequent raids to feed the Dublin slave emporium, perhaps the largest in western Europe. If Dublin falls which Irish kingdom stands most to gain? Do other Viking settlements fall quickly in Ireland and Scotland? How does the slave trade shift in western Europe? Any thoughts are appreciated.

 

[CHKeeley]

Leinster was in the middle of a war during this period so I don’t think they can do much to take advantage of it, but the Kings of Mide could try and have another crack at the town? There was certainly no love lost between them and the Norse throughout the preceding decades, but it depends on how weak the Dublin garrison really becomes after the defeat at Alt Clut. Then again, the Northern Uí Néill could intervene and prevent Mide from overrunning the territory. It has interesting questions for the broader expanse of Norse territories in the Isles.. I could see some Norse controlled areas of upper Scotland slipping back into native control, especially around Inverness and Ross. But places like the Hebrides and Orkneys are probably safe.

 

[cincpac overboard]

Leinster was in the middle of a war during this period so I don’t think they can do much to take advantage of it, but the Kings of Mide could try and have another crack at the town? There was certainly no love lost between them and the Norse throughout the preceding decades, but it depends on how weak the Dublin garrison really becomes after the defeat at Alt Clut. Then again, the Northern Uí Néill could intervene and prevent Mide from overrunning the territory. It has interesting questions for the broader expanse of Norse territories in the Isles.. I could see some Norse controlled areas of upper Scotland slipping back into native control, especially around Inverness and Ross. But places like the Hebrides and Orkneys are probably safe.

Regarding Ireland, if Mide captures Dublin before the Northern Ui Neill can intervene, does it seem likely that the Southern Ui Neill secure the high kingship of Ireland for themselves and no longer have to alternate with their northern rivals? What practical benefits does having the high kingship even entail? Certainly Mide would gain great prestige if after Dublin they could stamp out other Norse enclaves like Wexford and Limerick, receiving the endorsement for the kingship from Ireland's religious establishment.

On the Scottish front, with Dublin seized from the Norse and Alt Clut preventing access to the Scottish Lowlands, perhaps the Pictish kingdom isn't ravaged by Viking raids in the decade after the fall of Alt Clut. Perhaps the "great slaughter" of Picts the Annals of Ulster record in 875 CE never happens, butterflying the formation of the Gaelic kingdom of Alba after 900 CE. In fact, all the native kingdoms might come out stronger, preserving for at least another century the four-way division of OTL Scotland between Picts, Gaels, Angles, and Britons.