Ireland and Wales's ambitions of breaking the Anglo-French domination of the RBS Six Nations will be under scrutiny when the Celtic countries meet here at Lansdowne Road today.
Since rugby turned professional in 1995, England and France's monopoly of the championship has been interrupted only once, by Scotland, in 1999. However, during that same period, Ireland have established themselves as a credible 'third force' in European rugby, upsetting both the big boys on occasion although lacking title-winning consistency.
But they appear to have hit something of a brick wall of late and were well beaten in France last weekend.
Meanwhile Wales carried on from where they left off at the World Cup with a convincing opening round win against Scotland in Cardiff.
But Wales, for all their considerable first-half panache, faded after the break - something they cannot afford to do against Ireland who have won their last four meetings with the men in red shirts.
Ireland have captain Brian O'Driscoll back after the centre missed the Paris defeat with a hamstring injury.
That result confirmed the belief that without O'Driscoll Ireland lack a cutting edge; another established view is that when he plays all good teams have to do is stop him and they stop Ireland too.
And that may explain why O'Driscoll finds himself returning to a re-shaped back division. Coach Eddie O'Sullivan has taken the bold step of dropping Kevin Maggs, the rock of Ireland's midfield defence, and replacing him with wing Gordon D'Arcy, who made his first Test start against France.
D'Arcy is in O'Driscoll's regular Test spot of outside centre with the skipper in the No.12 jersey instead. However O'Sullivan has persisted in keeping Shane Horgan on the right wing rather than play him in his club position of inside centre.
D'Arcy, O'Driscoll and Horgan all play for Leinster yet not one of them is in their provincial places.
O'Sullivan was unapologetic. "We're going for a slightly different angle on midfield. We've two similar-type ball players. He (D'Arcy) is a different game-breaker from Kevin Maggs, more elusive, more capable of distributing from other parts of the field."
Up front Donncha O'Callaghan makes his first start, replacing the experienced Malcolm O'Kelly in the second row.
Wales skipper Colin Charvis misses the game with a finger injury, the captaincy taken by fellow loose-forward Martyn Williams, who was involved in creating two tries against Scotland, with Jonathan Thomas now completing the back-row.
But the pack is bolstered by the return from injury of hooker Robin McBryde and lock Robert Sidoli in place of Mefin Davies and Gareth Llewellyn respectively. "It's disappointing to lose Colin who has been playing good Test rugby as well as growing into a strong leader," said Wales coach Steve Hansen.
"It's now important that our designated lieutenants stand up and be counted in helping Martyn lead the side. We are looking forward to travelling to Dublin and playing a game of rugby we can all be proud of." Ireland: Girvan Dempsey (Leinster); Shane Horgan (Leinster), Gordon D'Arcy (Leinster), Brian O'Driscoll (Leinster, capt), Tyrone Howe (Ulster); Ronan O'Gara (Munster), Peter Stringer (Munster); Anthony Foley (Munster), Keith Gleeson (Leinster), Simon Easterby (Llanelli/WAL); Paul O'Connell (Munster, capt), Donncha O'Callaghan (Munster); John Hayes (Munster), Shane Byrne (Leinster), Reggie Corrigan (Leinster) Replacements: Frank Sheahan (Munster), Simon Best (Ulster), Malcolm O'Kelly (Leinster), Victor Costello (Leinster), Guy Easterby (Rotherham/ENG), David Humphreys (Ulster), Kevin Maggs (Bath/ENG)
Wales: Gareth Thomas (Celtic Warriors); Rhys Williams (Cardiff), Sonny Parker (Celtic Warriors), Iestyn Harris (Cardiff), Shane Williams (Neath-Swansea); Stephen Jones (Llanelli), Gareth Cooper (Celtic Warriors); Dafydd Jones (Llanelli), Martyn Williams (Cardiff, capt), Jonathan Thomas (Neath-Swansea); Robert Sidoli (Celtic Warriors), Brent Cockbain (Celtic Warriors); Adam Jones (Neath-Swansea), Robin McBryde (Llanelli), Iestyn Thomas (Llanelli) Replacements: Mefin Davies (Celtic Warriors), Gethin Jenkins (Celtic Warriors), Michael Owen (Dragons), Alix Popham (Leeds/ENG), Dwayne Peel (Llanelli), Ceri Sweeney (Celtic Warriors), Tom Shanklin (Cardiff)
Referee: Joel Jutge (FRA)