There is no rugby tournament in the world with greater tradition, which is as tribal and more central to the psyche of the game as the Six Nations.
The southern hemisphere's Tri Nations may be a better spectacle on the pitch, the Rugby World Cup may be bigger and provide more razzmatazz, but for a visceral and deep-rooted experience for the players, the coaches and the spectators, there is no equal to the annual battle for northern hemisphere supremacy.
Intrinsically linked to the action on the pitch, and the hype and build-up off it, the Six Nations is the result of more than a hundred years of bitter struggle between neighbours, jealous of the ephemeral and transitional nature of success that is each team's fortune down the years.
History weaves through it, too, and the rivalry that binds the tournament together echoes the enmity and alliances framed among the nations over the centuries.
The English Channel and the Irish Sea provide geographical dividing lines that separate France and Ireland from their archenemy England. For their part England in the eighth century dug Offa's Dyke, a huge trench designed to keep the Welsh out, that forms a scar between the two nations.
Battling with Scotland has long been a pastime too, and in 122AD the Roman Emperor Hadrian built his eponymous wall in order to keep control of the troublesome Scots.
The oldest fixture in the tournament is played between England and Scotland, two nations who first competed for the Calcutta Cup in 1879. That contest laid the foundation stone for what is now a multi-million dirham tournament, which down the years has provided theatre beyond any impresario's wildest imagination.
In 1990 amid a row about a tax that Margaret Thatcher, the British prime minister of the time, was keen to usher in, Scotland and England played out one of the most tense and climactic showdowns there has ever been in sport.
England had sailed through the tournament and arrived in Edinburgh for a clash with unbeaten Scotland that would decide the Championship.
David Sole, the Scottish captain, led out his team on to the Murrayfield pitch at an almost funeral pace and in a tournament first, the crowd sang the now famous folk song, Flower Of Scotland instead of the British national anthem, God Save the Queen.
Gavin Hastings, who played 61 times for Scotland as perhaps the country's greatest fullback, followed out Sole that day ahead of their famous 13-7 victory. He sees the tournament as a microcosm of the historical, political and cultural divide between the two nations.
"For many years, going back in history we have been warring with each other," Hastings said. "We've had great battles, the Bannockburns, the Cullodens, and to my mind we are replaying these battles on the sporting field instead of the battlefields. I think as long as you have that passion and tribalism then it makes for good sporting context."
Scotland have only had one other championship success since then, winning the last Five Nations tournament in 1999, and the Six Nations has proved a difficult hunting ground for the national team.
As a result, Murrayfield experienced falling attendances through the more recent stages of the new millennium until Andy Robinson, the former England manager, was appointed for the November internationals in 2009 and gave the squad a lift.
Scotland are by far the most improved side out of the six teams, and during the autumn they beat South Africa in front of a packed house at Murrayfield to record only their fifth victory over the Springboks.
"We are looking for all three of our home games to be sold out with fervent support," said Robinson, who coached England for two years after the 2003 World Cup. "The noise I heard during the South Africa game was tremendous. The lift that it gave the players was outstanding and I think the Scottish crowd understand that.
"For me our key purpose as a group of people is to inspire the nation though our winning performance. I believe that every time Scotland win through the courage that this side show, I believe that it does lift the nation."
Scotland's greatest wish is to consistently knock over the "Auld Enemy" and they are in a long queue to be the first.
In 2003 Imanol Harinordoquy, the French No 8 who has been recalled to the starting side to face Scotland tomorrow, revealed the extent to which the animosity between the two teams could be drawn out. "I despise them as much as they despise everybody else," the Basque forward said. "As long as we beat England I wouldn't mind if we lost every other game in the Six Nations."
It is a sentiment echoed, in slightly more dulcet tones, by Thierry Dusatoir, the French captain.
"Of course it is the biggest game for us," said Dusatoir, who did not miss a tackle during last year's tournament. "Firstly because it is England, secondly because it is the match on which we judge ourselves, and thirdly because we lost 34-10 there two years ago and that hurt."
England travel to Cardiff tonight to take on Wales in the Millennium Stadium, an arena that Martin Johnson, the England manager, has billed as, "the most hostile in the Six Nations for an Englishman".
England have not won in the heart of the principality since Johnson was a player, leading his side to a crushing 43-9 victory in 2003. The experience of that squad, who subsequently went on to win the World Cup, is but a faded memory.
Johnson's match squad of 22 features only five players that have experienced the wild atmosphere in the Millennium Stadium before. Mike Tindall, the captain, Mark Cueto, Andrew Sheridan, James Haskell and Nick Easter all remember painfully the 23-15 defeat there in 2009.
"There's a different feeling around the game in Wales than there is in many other places," Johnson said. "When you are in a hotel room in Sydney it is different to being in central Cardiff. The stadium is in the middle of town, it's all very tight."
If Cardiff is the most unforgiving atmosphere for an Englishman, then Paris is right down the list for a Scotsman. Scotland have beaten the French in Paris only twice in 42 years, a startling sequence that they wear like a hair shirt.
It was not always thus, however. France joined the Championship in 1906 and did not win a game until 1920, when they finally defeated Ireland 15-7 in Dublin.
France's early misfortunes turned around after the Second World War, and they embarked on a series of Championship victories during the 1960s.
They are now the third most successful team in the history of the tournament, behind England and Wales, and have dominated the Six Nations since Italy joined England, France, Ireland, Scotland and Wales in the 2000 season.
Unlike France, Italy struck gold at their first attempt, beating Scotland 34-20 at the Stadio Flamino in Rome. It was a stunning debut, but since that game Italy have recorded only six more victories in their subsequent 54 tournament matches. It is a poor return for the investment, but this year two Italian club sides, Treviso and Aironi, joined the Magners League.
"Without exposure to Celtic League rugby, Italian rugby had no chance of becoming more competitive," Nick Mallett, Italy's ultra-pragmatic coach, said.
"The standard is so much higher than the Italian Top 10. We want to be competitive in any game we play. A 10-point defeat away from home against any team in the competition is a good result. At home we are always aiming to win, though."
Ireland take on Italy in Rome tomorrow and after a 66-28 humbling at the hands of New Zealand in the summer Brian O'Driscoll, the Ireland captain, understands the pain that Italy go through as they try to pick themselves up off the canvas each time after a heavy defeat.
"You learn that Test rugby is not easy. No national team are going to lie down and give you the match," said O'Driscoll, who is the leading scorer in the Six Nations with 22 tries.
"Sometimes you need to learn harsh lessons to move on because next time you get an opportunity you make sure you will bring your best game. I'm sure at some stage Italy will beat Ireland, let's just hope it is not this year, and not for some time to come. It's a ruthless environment."