This month marks the 1,000th anniversary of the Battle of Clontarf on Good Friday, April 23, 1014 which led to the slaughter of Ireland's most famous High King and – according to legend – banished the invading Vikings.
To mark the occasion, Viking enthusiasts are travelling from New Zealand, Australia, Canada, the US, Scandinavia and Europe to take part in Ireland's biggest ever re-enactment of the battle
But according to Trinity College historian and Boru scholar Sean Duffy (above), the notion that Boru's forces actually banished the Vikings from Ireland "is a popular myth".
While Boru's side was victorious, he himself perished in the battle; he was decapitated by the avenging Viking Brodar while he was praying in a tent.
But the victory at Clontarf not so much sent the Vikings packing as it prevented Ireland from being invaded by the marauding Danes, according to Mr Duffy.
"At that time the UK had been conquered by the Danes and they were attempting to conquer Ireland as well," he said.
"It was a major international event," he added, saying it is more likely that the actual death toll was evenly split to about 1,000 on either side.
Back then, battles typically lasted for about an hour.
But the fact that the Battle of Clontarf raged the entire day from sunrise to well after sunset was largely unprecedented, and reinforced Boru's reputation as a force to be reckoned with.
Aside from all this, Boru was said to be 73 at the time of the battle, which was no small feat given the average life expectancy then was only around 30.
Reports of the battle recorded in the "Cogadh Gaedhel re Gallaibh" or "The War of the Irish with The Foreigners" and other accounts suggest the Vikings arrived in their longboats on the incoming tide at dawn at what is believed to be the eastern end of Clontarf near Fairview.
Although there is much conjecture today as to the location of the actual battleground – with some historians believing it extended as far as the River Tolka near the Ballybough Bridge near Drumcondra – Mr Duffy believes the centre of the battle was more likely situated in what he calls the "old heart of Clontarf" where the medieval Clontarf Castle remains today.
He also believes that the legendary Caill Tomair woodland to where the retreating Vikings reportedly attempted to flee towards Dublin was actually another, less celebrated tract of oakwood that was quite a bit closer to Howth.
The tide quickly receded, taking the longboats out to sea and leaving the Vikings stranded while being beaten back towards the sea by Boru's forces, where they drowned.
"This drowning of a multitude of warriors is well reported," said Mr Duffy. "They were inundated and pushed back to the sea."
While the battle is celebrated as Boru's greatest victory after five decades of military accomplishment under his belt, Mr Duffy said it appears he probably didn't take part in any actual fighting himself due to his advanced age, but acted as a general instead.
However, he said Boru was likely killed by chance as the Vikings happened upon his tent as they were fleeing.
And being a religious man on Good Friday, he said it's also very likely that "he probably was kneeling praying when he was captured and had his head chopped off".