In the Mabinogi, the Welsh mythology of the Middle Ages, Bendigeidfran is a giant and king of Britain who appears in several Welsh Triads, most notably Branwen Ferch Llyr.
During that legendary tale, he leads a Welsh army to battle in Ireland. They appear to be marooned when a bridge they are about to use is destroyed, but Bendigeidfran then lies across the river, allowing the Welsh soldiers to use his enormous body as a bridge.
With its earliest manuscript dated to the 14th century, but believed to be much older, the story has been retold and adapted in various different ways and remains popular today.
At the Principality Stadium last Saturday, it felt as if the role of Bendigeidfran was being reinterpreted in new and heroic means.
Alun Wyn Jones is the giant who leads Wales on the rugby field, and it was the captain putting his body on the line to lead his men into combat against their Irish adversaries.
He did so with a colossal performance, as he had done throughout the competition, as he has done throughout his career.
And then six days later, Jones was voted the Six Nations player of the tournament - a clear and deserving winner.
Even for a man whose legendary status had long been secured, Saturday's triumph seemed like a coronation for this titan of the game.
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Wales' greatest? Europe's greatest?
The fervent Cardiff crowd was momentarily silenced in the eighth minute as Jones sat on the turf to receive treatment on an injured knee; an entire nation holding its breath as the medics applied bandages to the wound.
Even for a Wales team who had won their previous 13 matches - a national record - losing such a totemic figure would have been a severe blow to their hopes of securing the Grand Slam.
But Jones was not going to be denied, not on his 125th appearances for Wales and with a third Slam in his sights.
His was a performance of searing intensity, carrying the ball more than any of his team-mates, making 19 tackles and tormenting his opponents at the breakdown.
It was a monumental effort, typical of a man for whom extraordinary feats seem ordinary.
It is why the magical former fly-half Jonathan Davies, now in the commentary box, said at the end of the game that Jones is "maybe the greatest player Wales have ever had".
Davies was not alone. Martyn Williams, an ex-Wales flanker with two Grand Slams to his name, ranked Jones alongside England's World Cup-winning Martin Johnson among the best second-rows of the modern game.
Will Greenwood, a member of Johnson's triumphant team of 2003, went further by declaring in his Telegraph column on the morning of the match that Jones is the greatest player to have emerged from the northern hemisphere in the 21st century.
And then speaking on BBC Scrum V on Sunday, Jones' former Ospreys coach Sean Holley suggested the lock is a future First Minister of Wales. The man currently in that role, Mark Drakeford, may well have been looking over his shoulder when he joined Jones and the rest of the Wales squad for their celebratory ceremony on the steps of the Senedd on Monday night.
For Jones, the tributes kept coming, stacked higher than the mounds of empty chip boxes discarded on the streets of Cardiff in the early hours of Sunday morning.
And while praise for a player of Jones' standing was nothing new, there was a feeling that rugby union at large was convening to rubber-stamp his greatness on a global scale.
'Uneasy lies the head which wears the crown'
At 6ft 5in and over 18 stone, Jones is a bulwark built for the brutal rigours of Test rugby.
But while those broad shoulders are accustomed to carrying the weighty responsibility of captaining a zealous rugby nation, adulation does not rest so easily.
In an international career spanning 13 years, Jones has won four Six Nations titles - including three Grand Slams - and toured with the British and Irish Lions on three occasions, helping captain them to victory in Australia in 2013 and playing a prominent role in the drawn series in New Zealand four years later.
He has also won league titles and cups with his home region, the Ospreys, and racked up several individual honours along the way.
Jones, however, doesn't really like to talk about all that.
A reluctant interviewee, he will brush off talk of milestones and historic achievements - seemingly trivial distractions for a man preternaturally driven and focused on the next task.
It is that single-mindedness which underpins his fierce competitive edge on the field, the fuel for a relentless work ethic.
Ask him about previous matches or statistics, he will give you short shrift. Offer praise - from pundits or even his peers - and he will modestly change the subject.
Jones sometimes seems as if he is building a barricade between himself and the media, but he will occasionally drop that granite façade.
One such example provided one of the abiding images of Wales' latest Grand Slam.
As he stood for the anthems, Jones noticed the mascot, seven-year-old Joey Hobbs, was shivering in the wind and rain, so the captain took off his tracksuit jacket, bent down and wrapped it around the boy's shoulders.
Afterwards, Jones told Joey he could keep the jacket and his family are now planning to frame it in their house.
It was a simple, but tender act of kindness from a man who was about to engage in 80 minutes of shuddering Test rugby.
It was also another insight into the make-up of the man behind the legend, a formidable athlete and intimidating opponent, but also father of two young girls, a human being.
Leaving a legacy
At the Wales team headquarters in the Vale of Glamorgan, there is an indoor training centre known as the Barn, where the walls are adorned with inspirational messages.
Some change, others come and go, and two phrases which have stood out in recent years are 'Yesterday is in the past' and 'How do you want to be remembered?'.
They could have been written by Jones.
The first speaks of the importance of seizing the moment, summoning the effort and sacrifices which got you here and then focusing on how best to execute the team's plans.
The second is about harnessing the power of history, making an impact and leaving a legacy.
There was a time when Welsh rugby weighed itself down with history. During the 27 barren years between the 1978 and 2005 Grand Slams, there was only looking back, a pining for the glory days of a bygone era.
And while the golden generations of the 1970s are still revered, the success of Warren Gatland's reign has given the Welsh public another chance to revel in the present day.
Jones and Gatland's axis of power
When he arrived in 2007 with the team at one of its lowest ebbs, Gatland spoke about restoring pride in the Welsh jersey. There are few who have done so like Jones.
The two men have formed a lasting axis of power at the head of Welsh rugby. On Saturday, Jones was the only survivor from Gatland's first Grand Slam in 2008.
Both are pragmatists with an eye for detail, embracing the sport science, psychology and forensic search for 'marginal gains' which modern rugby demands.
And yet both are acutely aware of the importance of Welsh rugby heritage, particularly Jones, Swansea born and bred and a passionately proud Welshman.
Like every other young boy braving miserable Welsh weather to play grassroots rugby, Jones' dream while playing for his youth club Bonymaen was, one day, to wear the red shirt of Wales.
He has done so 125 times by now, as well as making nine Test appearances in the red of the Lions - but he never takes what he calls this "privilege" for granted.
It is a well-worn cliché that players should approach every game as if it is their last, and there was more than a hint of finality to Jones' display on Saturday, not only in the ferocity of his performance but in that quiet moment when, long after the final whistle and the Principality Stadium had emptied, the lock sat alone on the side of the pitch, still in his kit, silently contemplating all that had happened.
True to form, Jones had already spoken about his next target - the World Cup in the autumn - but here was the man who always looks forward, taking the time to look back.
When Wales' players pull on the red shirt, they carry the memories of those who wore it before them.
They are told to respect the jersey, and they do so with wholehearted displays and utter commitment on the field.
They are living in the moment, but aware of who went before them, building on their legacies and adding to their stories.
Nobody embodies that more than their leader, their giant: Alun Wyn Jones.
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