There is little love lost between the two teams who provide the most alluring fixture in the 2012 Six Nations' first weekend according to The Observer's Eddie Butler.
"Perhaps the most alluring fixture of the opening weekend is Ireland v Wales in Dublin on the Sunday. The two countries are often bracketed together in some Celtic cousinhood, allies against the interests of countries blessed with more money and greater playing numbers.
"This may well be the case in the corridors of rugby politics, although it has been said that the only people who trust a Welsh-Irish alliance less than the rest of the rugby-playing world are the Welsh and the Irish themselves. On the field there is little love lost between them. By tradition it is a healthy rivalry; of late it has been cranky.
"...For evidence of sourness, how about the head to head between Gavin Henson and Brian O'Driscoll in the grand slam showdown of 2005, a duel that went the Welsh player's way on the day? Or the reception for Henson the following season when he came off the bench, a battle of wills comprehensively won by the Dublin crowd?