The annual meeting between Ireland and Wales comes down the tracks this weekend. Misty-eyed mythology decrees that the Irish and the Welsh should be Celtic soul brothers, bonded by their shared dislike of the big bad English wolf. 

Anyone who follows rugby will know that this is emphatically not the case and hasn't been for at least a decade. (As Philip Browne says, in rugby terms, "the one country that always supports Ireland is England."

But how did Ireland and Wales become the spikiest rivalry in the Six Nations?

In the beginning: We dislike the Irish the most (2009)

In the Irish telling, the needle started when Warren Gatland decided to ramp up the tension ahead of Ireland's Grand Slam tilt in Cardiff in 2009 by revealing that, of all the Six Nations teams, the Welsh players disliked the Irish players the most. 

By the time the papers hit the next morning, the word 'dislike' somehow morphed into the word 'hate' and, lo, a new narrative was born. 

There was, Gatland claimed later on, a large compliment underlying those words. The Wales coach indicated the dislike stemmed from the fact that his players had miserable experiences of playing against Irish players, especially at club level.

But this dimension was ignored amid the hurt that the Welsh were now telling us that they hated Ireland more than the English. What had we ever done?

One suspects that those Austin Healey types among the English rugby fraternity - the lippy motormouths who revel in their own reputation for arrogance - were also miffed that their mantle had been stolen.

But the chief hurt came from the over-sensitive Irish. 

No one could accuse Declan Kidney of being a trash-talker supreme and so he stayed emollient at all times that week.

Even after Ireland's famous two-point win, he passed up the chance to deliver a boo-ya smackdown to all of his team's many critics in the valleys.

Menopausal warthog (2010)

Eddie O'Sullivan and Warren Gatland during their years working together with Ireland

If Declan Kidney was disinclined to fire a call-out DVD straight round to the Gatland household, then the gentlemen of the Irish press corps weren't quite so restrained.

Before the 2010 meeting in Croke Park - a game which Ireland won handily - Vincent Hogan, respected Irish Independent columnist and Eddie O'Sullivan ghost-writer, wrote that Gatland's personal gripe against Ireland made him as "snappy and rational as a menopausal warthog". 

This gripe went back to Gatland (or "Wazza" as the Irish press was to soon derisively start calling him) being abruptly sacked as Ireland coach at the end of 2001 after two years of rapid improvement. 

Oh how it was all so rosy once between Ireland and Gatland.

Talking to RTÉ Sport before this year's Six Nations, Victor Costello praised Gatland for rescuing Irish rugby from the icy and loveless embrace of Brian Ashton and, as national team coach, tapping into the burgeoning provincial scene in the late '90s.

Once Ashton finally decided, in the middle of the Five Nations, that he couldn't stick the sight of Irish players kicking the leather off the ball anymore, Gatland was hurriedly installed as national team coach.

His first couple of years were tough - though Irish rugby fans were used to tough times then - and it contained a real low point in the World Cup loss to Argentina in Lens. 

But, powered by the infusion of talent from the newly flourishing provinces, Ireland took wing at the turn of the millennium, beating France twice on the trot and then stopping England winning the Grand Slam in the foot and mouth interrupted 2001 season. 

His sacking, when it arrived, was a big shock to many. 

The IRFU evidently agreed with George Hook's hypothesis that backs coach Eddie O'Sullivan was the real whizz behind Ireland's sudden revival at the turn of the millennium and decided to cut Gatland loose. 

They may also have been influenced by Keith Wood's exasperation with Gatland's failure to hire a specialised defence coach - something which also bugged the methodical O'Sullivan. 

Both O'Sullivan and Wood would get it both barrels from Gatland in his second international coming as Wales coach, with the latter being described as a 'mé féiner' following his criticism of Gatland's third test selection.

Welsh ascendancy (2011-12)

Mike Phillips tearing over in the corner to score Wales's 'controversial' only try in 2011 Six Nations game

After years of Irish dominance in the fixture - it was 13-4 in the head to head between 1995 and 2010 – the Welsh enjoyed a run of results in the early part of the present decade. 

The Welsh being the Welsh, they managed to re-cast the 2011-12 period as a long era of unbroken success while presenting the previous 16 years as a mere temporary blip.  

The most significant win came in the World Cup quarter-final in Wellington – in bragging rights terms, worth about five Six Nations wins – and the Irish could have little to complain about after that bitter defeat.

They could – and most certainly did – complain about the loss earlier in the year. Wales won the 2011 Six Nations encounter thanks to a farcically illegal try scored by Mike Phillips.  

The Welsh didn't take kindly to Irish whingeing on the issue. 

In his post-match interview, James Hook suggested that the Philips try was payback for various and unspecified incidents of grotesque good fortune that Ireland had enjoyed during their long winning streak in Cardiff.  

This sentiment was echoed many times over on Welsh social media, though the most recent instance of outrageous good fortune that anyone could instance was a dodgy Paul Dean try in 1989. 

Dropping O'Driscoll (2013)

Brian O'Driscoll in his squad suit for the third Lions test in 2013

The joy of the Lions, for many fans of the constituent nations, is less about seeing them actually win the series and far more about how many of your country's players make the starting XV. 

Brian O'Driscoll was nearing the end of his playing days in the summer of 2013 - indeed he had originally intended to retire that year before the prospect of working at international level with Joe Schmidt coaxed him into giving it one last shot.

But he was still thought to operate on a higher plane to Welsh centre Jonathan Davies, at least by Irish pundits. 

Gatland saw it differently and dropped him from the match-day squad for the deciding test against the Wallabies.

Davies was picked in his stead, along with nine other Welshmen in the starting XV. 

Cue uproar. Emergency podcasts were produced as sportscasters sought to grapple with the news, fans and talking heads openly offered their support to the Australians. 

Heretics finally felt comfortable in admitting that they never really had much grá for this Lions concept in the first place anyway.    

Viewed from the cooler light of day in 2018, many will concede there was an over-reaction, and a vaguely embarrassing one at that. 

Gatland's defenders can point to the scoreboard - as Gatland's defenders have often been able to do - after the third test and say he was vindicated. 

Not all Welsh observers were happy with Gatland's team selection for the final test.

The Western Mail's Andy Howell found fault with the line-up on the basis that there wasn't enough Welshmen in it. 

Flora (2015)

It's hard to believe there's another nation on earth which obsesses more about what foreigners think of them than Ireland (to those in online media, 2014 will always go down as the year of the British Twitter reaction to hurling) but Wales may be one such country. 

It's three years now since the Welsh press exploded in rage at Neil Francis's puckish assessment of Warren Gatland's intellectual capabilities.

Francis, in case anyone forgets, wrote that Gatland had the "intellectual properties of a tub of flora". In the very next clause, he did credit Gatland with having a certain 'instinct' and acknowledged that he was a winning coach but, perhaps understandably, these qualifications failed to soften the effect of the original barb.

Francis can claim to be ahead of his time in the matter of riling up the Welsh. Before Ireland's 29-23 win over Wales in Wembley in 1999, he presented a promo for RTÉ in which he expressed bafflement at Wales's perennial over-confidence and mocked their harking back to the 70s. 

"They prefer to regurgitate the chateaubriand of the '70s rather than sample the fish head soup of the 90s. Reality has hit home but, 20 years on, they still can't face it," he said.

There was no Twitter in 1999 and so no one Welsh, apart from Tony Clement in the RTÉ studio, actually saw the clip.

Alas, that was not the case in 2015. 

The Welsh press, most notably Wales Online - the online version of the Western Mail - seized on the comments and produced something in the region of 1,000 articles on the column (rough guesstimate).     

Rob Howley delivered one of those 'more in sorrow than in anger' homilies, saying it was a shame to see things becoming personal. 

Tony Copsey, the English-born copper who infamously decked Francis in the early stages of the dismal 1992 Five Nations encounter, tweeted that "another slap" might be in order.

Francis didn’t bear the burden of Welsh outrage alone as Keith Wood shipped another blast for being allegedly too cocksure about Ireland’s chances in Cardiff.

After Wales's rousing seven point victory, the Western Mail produced their famous ‘Memo to Cocky Irish Pundits’ front page.

Where are we now? (2018)

It's possible that 2015 marked the high-water mark of the Wales-Ireland spikeyness.

Shane Williams wrote before last year's encounter that the Welsh players never disliked the Irish players and that was just Gatland mischievously lobbing grenades in Ireland's direction.

The dislike narrative exists now as a media phenomenon more than anything else. 

Welsh and Irish websites eye each other warily this week for signs of slight. Interns have probably been told to monitor Wales Online all week in the hopes of finding something incendiary.

What do we have to work with this week to incite people?

Sean O'Brien's bewilderingly harsh assessment of Gatland's management of the recent Lions tour? (He was there, I suppose) Wales screwing us in the 2023 World Cup bid? Or what about that UKIP politician who wants the Irish to pay for the up-keep of Welsh roads?

We've made taller mountains out of smaller molehills in the past. 

Follow Ireland v Wales on Saturday (KO 2.15pm) via the live blog on RTÉ.ie/Sport and the News Now App, or listen live on RTÉ Radio 1, with commentary from Michael Corcoran and Donal Lenihan.