Back in 2009, Wales coach Warren Gatland said his players disliked their Ireland counterparts more than any other team in the Six Nations.

Is Warren Gatland on a personal crusade against Ireland? Do Scotland really employ dirty tricks to disrupt England's route to the stadium in Murrayfield?

Ireland v Wales or Scotland v England? Which is the biggest grudge match?

Have your say, tweet #bbcsixnations or text 81111.

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Former Ireland international and British and Irish Lions lock Donncha O'Callaghan has written a feisty column in today's Times.

It's basically a history of grudges between the sides, and a detailed explanation of how to hold one.

Gatland is apparently sour about being sacked by Ireland and a lack of respect in the world of rugby.

O'Callaghan says Ireland should see Gatland as the man who dropped Peter O'Mahony from the match-day 23 after one Test as Lions skipper, dropped Brian O’Driscoll from the 23 in the 2013 Lions series, and did not give Rory Best a decent shot in last summer’s tour.

You can read the full rant here., external (But a subscription is required, sorry.)

Richard Williams
BBC Sport Wales at the Aviva Stadium in Dublin

Grey skies, freezing temperatures and several thousand rugby fans curing hangovers with the hair of the dog.

Dublin on matchday is a colourful spectacle, sparkling with electricity at the prospect of another titanic battle between the celtic cousins.

Ireland v Wales has served-up some of the most intense, nail-biting physical confrontations of recent years – and the pundits say this one is too close to call.

Can Ireland overcome a huge hurdle on the road to a potential grand slam showdown with England on St Patrick’s Day? Can Wales keep their challenge alive after the TV replay heartbreak of Twickenham?

And who’s the TMO?

Big questions ahead of the big game. Dublin is buzzing.

Right, without further ado, let's head to Dublin for the first match of the day.

Looking a bit gloomy over there... is running rugby off the cards?

We're all expecting a kicking contest anyway.

Image source, BBC Sport

Here's how to follow today's two titanic tussles:

14:10-16:40 - Ireland v Wales, BBC Radio 5 live sports extra, BBC Radio Ulster, BBC Radio Wales & BBC Radio Cymru

16:00-19:00 - Scotland v England, BBC One, BBC Radio 5 live, BBC Radio Scotland

Along with our live text commentary of course.

First there's this...

Image source, Getty Images

Then we bring you this...

Image source, Getty Images

Get set for a spectacular Six Nations Saturday showdown!