Constantine I

A by no means contemporary portrait of Constantine I

Constantine I

Constantine I had the misfortune to come to the throne at a period of peak Viking, with the likes of Olaf the White, Ivar the Boneless and the Great Heathen Army swarming across the kingdoms of Ireland, England and Scotland. Kingdoms were falling and kings brutally murdered all across Britain but could Constantine find a way to survive?

Listen to Constantine I’s podcast episode here or read on to find out more.

Backgroundy Stuff

The idea of a country called “Scotland” did not yet exist and instead, what we now call Scotland was made up of several different peoples:

  • Picts – the resident Celtic peoples in north and north-east Scotland
  • Scots – Irish settlers in the kingdom of Dal Riata in western Scotland
  • Britons – the native southerners pushed up to the south-west of Scotland by the…
  • Saxons – the new power in England, pushing into south-east Scotland via the kingdom of Northumbria

The Picts had threatened to become the permanently predominant kingdom at the start of the ninth century until all their leaders were wiped out in one battle in 839 by raiders from Scandinavia – the Vikings. This left a power vacuum which was filled by Kenneth MacAlpin, who became king of both Dal Riata and the Picts in the 840s. Kenneth was a strong king who was largely untroubled by Viking invasions and made marriage alliances with Aed Findliath (High King in Ireland) and Artgal, king of the neighbouring kingdom of Strathclyde.


Constantine I was the son of Kenneth MacAlpin, so was known as Causantín mac Cináeda (Constantine son of Kenneth). We don’t know exactly when he was born but it must have been no later than 858 (the year his father died) and, given that he became king in 862 and was not said to reside in a cot, was probably born in the early 840s.

The reason that Constantine I did not succeed his father in 858 is that the Scots in this period seem to have operated a system of alternating succession, whereby the king’s brother would first inherit the throne before it then went to his sons. Thus in 858, Constantine’s uncle, Donald I, became king, and Constantine succeeded on his death. The benefits of the system were ensuring an adult male succeeded and finding a way to manage the rival claims (i.e. everyone gets their turn!)

As is the case with all of these early kings, we don’t know anything about Constantine’s life before becoming king. And, as it happens, the sources are not particularly prolific in providing insights into his life as king. Though the Prophecy of Berchan (a long historical poem presented as a prophecy of Scottish history but in reality written after the events) gives him the nickname of An Finn-Shoichleach (the wine-bountiful), so perhaps Constantine enjoyed a drink in his Pictish palaces!

However, this is a crucial period in the history of Britain (or the Atlantic Archipelago to include Ireland without being political!) and while not always at the centre of events, Constantine was very much caught up in the whirlwind that was the Vikings and the Great Heathen Army.

Vikings (not the TV show, though be warned that there are potential spoilers!)

Ragnar Lodbrok and son (Bjorn Ironside) from TV show Vikings

Ragnar Lodbrok and son (Bjorn Ironside) from TV show Vikings

The Great Heathen Army arrived in England in 865 with the intention of conquering the various Anglo-Saxon kingdoms that constituted England in this period. The army was a large force of warriors from across Scandinavia, probably looking for an easy target after finding French defences now too strong for their liking. By legend, however, the army was led by the sons of the legendary Ragnar Lodbrok, eager for vengeance after their father was killed by Aelle, king of the Northumbrians. This fearsome army landed in East Anglia in 865 and were met by King Edmund, who rather sensible gave them food and money and encouraged them to bother somebody else.

The activity (in England) of the Great Heathen Army

The activity (in England) of the Great Heathen Army

In 866, the army were joined by another supposed son of Ragnar, Ivar the Boneless, who had been helping Olaf the White to establish himself as King of Dublin. They captured the city of York from the Northumbrians and the following year defeated the two rival kings for Northumbria, Aelle and Osberht (who had joined forces to fight their common foe), after which Aelle was supposedly blood-eagled and vengeance complete.

Thus far, none of this was of immediate concern to Constantine I in Scotland. However, these were not the only Vikings in the area and while Ivar the Boneless was blood-eagling the Northumbrians, his ally in Ireland, Olaf the White, was also on the look-out for somewhere to plunder. Unfortunately, he chose Scotland, heading deep inland to take plunder, hostages and find somewhere to hang out over winter. This might have represented a terminal threat to the embryonic kingdom were it not for Constantine’s brother-in-law Aed Findliath (he of the marriage alliance with Kenneth MacAlpin fame) taking advantage of Olaf’s absence in Ireland by destroying his longphorts and various military camps. Consequently, Olaf abandoned Scotland to re-establish himself in Dublin.

King Edmund of East Anglia in the process of becoming Edmund the Martyr

King Edmund of East Anglia in the process of becoming Edmund the Martyr

Further south, the Vikings returned to East Anglia in 869, defeated the Saxons in battle, tied King Edmund to a tree and shot him full of arrows (apparently at Ivar’s instigation). Also by 869, Olaf had reasserted himself in Ireland and seems to have sent a message to Ivar the Boneless suggesting that he come north to help him annihilate a kingdom in the north of Britain. Thankfully, for Constantine I, this was the kingdom of Strathclyde. In 870, Olaf and Ivar besieged the major fortress of Dumbarton Rock for four months until the well dried up, at which point they stormed in, destroyed the capital and took hundreds of slaves. To add insult to injury (or rather, even worse injury to injury) in 872, Artgal (the king of Strathclyde and also of the marriage alliance with Kenneth MacAlpin fame) was assassinated.

But what about Constantine? Intriguingly, it is said that Artgal was killed on Constantine’s suggestion, implying that while Olaf was wintering in Scotland in the 860s, Constantine may have struck a deal with him and encouraged him to focus his wrath on Strathclyde. Thus Constantine managed to stay out of trouble and remove a rival without having to put himself at risk. 872 appears to be the year when Constantine decided to play his hand, because not long after Artgal’s death, Constantine encountered Olaf raiding the coast and killed him in battle. In 873, Ivar went to Ireland to establish himself as king and then died himself. Suddenly, things were looking very rosy for Constantine!

Unfortunately, there are always more Vikings and the new man in charge, Halfdan, was just as deadly. In 874, he drove the Mercian king into exile and the following year established himself as king in York. He then started making his way to Ireland and in the process defeated Constantine in the Battle of Dollar. Luckily, Constantine lived to tell the tale and then even more luckily, Halfdan was killed in Ireland in 877.

Less luckily, however, a few months later Constantine encountered another Viking force (possibly Halfdan’s men returning from Ireland) and was defeated in battle at Inverdovat. What’s more, this time his luck had truly run out and he was killed, either in battle or possibly executed on the beach afterwards.

State of The Nations

Before we review Constantine I, it’s probably good to catch our breath and have a quick look at what has been left in the wake of all this Viking plunder:


The Vikings have established a ruling dynasty in Dublin but there is still ongoing conflict between native Irish kingdoms and other Viking settlements across Ireland.


The Great Heathen Army has led to the fall of East Anglia and Northumbria while Mercia is largely under Viking control. However, when Halfdan went north he left Guthrum to complete the conquest of southern England and the kingdom of Wessex. Instead, Guthrum was defeated by Alfred the Great, who began a process of pushing the Vikings back and establishing a unified Anglo-Saxon kingdom: England.


The destruction of Dumbarton Rock saw the abandonment of the Strathclyde capital, with a new kingdom emerging based around Govan (Glasgow) and stretching down to Penrith (now in the English Lake District). This kingdom would also come to be known as Cumbria. For Constantine I, however, his kingdom remained largely intact and independent despite the Viking assaults – other than his being killed, it couldn’t have gone much better!



Given the fact that Constantine’s biography largely consisted of what other people were doing, you might not expect much positive action from him and to an extent you would be correct. However, that is not to say that Constantine does not enjoy some success. He may well have encouraged the Viking attack on Dumbarton Rock or at the very least the assassination of Strathclyde’s king, thus increasing his dominance in the region without actually having to risk a battle himself. He then had a rather unexpected victory against the Vikings in which he put an end to the mighty Olaf the White. And despite the chaos of the Viking invasions, the country remained pretty much intact, perhaps because Constantine deliberately sought to avoid battle and encourage the Vikings to focus elsewhere.


Constantine's Cave - by legend, where Constantine I spent some time before or after his final battle.

Constantine’s Cave – by legend, where Constantine I spent some time before or after his final battle.

If we’re honest, Constantine I’s military record is not really something to write home about. In 866-67, Olaf came deep into his territory, plundered the nation and stayed there over winter (no doubt at great cost to the locals). It may only have been the positive action by Aed Findliath in Ireland forcing Olaf to depart in 867 that prevented a more permanent settlement. Constantine’s role is then little more than passive, getting the Vikings to fight Strathclyde is not as impressive as doing it himself and he probably happened upon an unprepared Olaf. Otherwise, he was defeated by Halfdan at Dollar in 875 and then killed in 877 by the Vikings, apparently having spent some time hiding out in a black cave.

Our Verdict

Constantine did not suffer conquest or devastation to the Vikings and his tactics of keeping them occupied elsewhere could have worked…but ultimately he was defeated and never showed any real aptitude in actual battleyness.

Score = 6.5/20



Rather like his father, Kenneth MacAlpin, Constantine I does seem to have been a crafty so-and-so. The Irish annalists suggest some form of collaboration with the Vikings and Constantine was far from a noble patriot defending his territory to the bitter end like Alfred the Great in Wessex. Instead, Constantine encourages them to attack the nearby Strathclyde AND assassinate their king (who’s son, let’s not forget, was married to Constantine’s sister!) and some historians have speculated that he may even have encouraged the Vikings to plunder the parts of his kingdom that were not so loyal to him. And of course after Argtgal’s death he kills Olaf – clearly not a man to be trusted!


There are no naughty bedroom antics with Constantine I to entertain us and we may be paying him an undue compliment for his skullduggery. Perhaps, rather than a crafty Kenneth figure he was instead more vacuous Vichy – acquiescing with the invading force and getting a bit lucky from time to time when other people were killed instead of him.

Our Verdict

We give Constantine the benefit of the doubt here – in the sense that he was a crafty, untrustworthy source of skullduggery and plotting! However, it’s all a bit “all’s fair in love and war” and lacks anything truly debauched or monstrous to get a high score.

Score = 9/20



If Constantine was able to persuade the Vikings to leave his people alone (and encourage them elsewhere) then this would have been of benefit to the lucky ones that were spared Viking plunder. Some historians have assumed that this would have been exclusively his Gaelic followers but he has also been celebrated in Pictish histories, described as being the “cow-herd of the byre of the cows of the Picts” (i.e. the shepherd of his people) and is sometimes listed as the 70th and final King of the Picts.


The fortress of Dumbarton Rock may have fallen thanks to Constantine's meddling

The fortress of Dumbarton Rock may have fallen to the Vikings thanks to Constantine’s meddling

It may be that Constantine protected some areas from the worst of the Vikings but in reality, a lot of Scots would have suffered terribly in this period. According to the Annals of Ulster, in 866-67 Olaf “plundered the entire Pictish nation and took hostages from them.” That he stayed for several months implied a torrid time for anyone nearby. The sacking of Dumbarton Rock required 200 ships to transport the English, Britons and Picts to the slave markets of Dublin – even if Constantine did not care about these people, it’s hardly an occurrence with which to commend his just rule! Indeed, in terms of positive action on this front, we have nothing to suggest Constantine did very much at all and can probably assume a lot of Viking atrocities that have been forgotten by history.

Our Verdict

This was a difficult times for all the kings of Britain and Ireland and perhaps Constantine may have lessened the hardships for some of his people but overall it was still a torrid period of Viking raids and would not have been a good time to be a subject.

Score = 4.5/20


Constantine was king from 862 to 877 – a reign of 15 years which, when converted into a score out of 20 (where 20 is the longest reign of all the monarchs), is a score of  5.20.


We know of one legitimate surviving child for Constantine I (the future Donald II), which gives him a score of 2.22

Total Score = 27.42

Rex Factor

Constantine I was a largely passive figure for most of his reign and perhaps this cautious tactic could have worked if he had not been killed in 877 and had instead managed to see off the worst of the Viking invasions. If his luck had held, perhaps he would have ruled for another twenty years and rebuilt the country. Instead, he acquiesced and tried to keep his head down low while the Vikings ran amok, thus leaving him rather a somewhat unimpressive record.

Our Verdict: No, Constantine I does not have the Rex Factor.


What do you think – does Constantine I deserve the Rex Factor? Vote in our poll below and tell us what you think!

13 thoughts on “Constantine I

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  11. Gentlemen, I am not endorsing Constantine I for the Rex Factor but i believe you have to give him some credit for holding off the VIKINGS for 15 years. Most were not able to come close to that, granted he threw his neighbors under the viking’s boot.

    • He deserves some credit, I agree – 15 years is a surprisingly long time and he was kind of unlucky in the end to be killed after surviving all the main Viking leaders. On the other hand, I suspect he was pretty lucky at the same time to have lasted that long and that his kingdom was not then significant enough to bother conquering. Good work by Constantine in screwing over the Strathclyde Britons!

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