By James Helm
BBC News, Dublin
When the England squad's preparation includes a history lesson, you know that this is no ordinary rugby international.
Croke Park is hosting its first Ireland v England Six Nations match
Irish fans have been relishing this moment for a long time and finally, after all the debate about national anthems, the match is finally upon us.
Earlier this week, Conor O'Shea, the former Ireland international who now works for the English Rugby Football Union, was given the task of explaining the significance and history of Croke Park to England's players.
This magnificent stadium in north Dublin is much more than simply Ireland's - and one of Europe's - finest sporting venues.
It is the headquarters of the Gaelic Athletic Association, and the beating heart of Ireland's most popular sports, Gaelic football and hurling.
It is the focal point of these sports which are played right across the country, from the smallest villages to the biggest cities, and which have long been closely identified with Irish independence and identity.
So the decision by the GAA to open up Croke Park to what used to be referred to as "foreign games" was a huge deal here.
Ireland's rugby union and soccer teams are being allowed to use "Croker", as it is affectionately known, while their home across the River Liffey, Lansdowne Road, is redeveloped.
The first game, against France two weeks ago, was an enormous occasion, even if it fell a little flat when France scored a late try to edge victory.
Ireland beat England in 2006 and took the triple crown
Irish rugby fans would admit, though, that it was the England game that they were really looking forward to.
Match tickets are like gold dust, with newspapers full of stories of their inflated prices on the thriving black market.
This is a game Irish rugby fans are desperate to see. Their team, after all, has an impressive recent record over their white-shirted rivals, and they are firm favourites to win.
Then there is the history. Croke Park was the scene of a notorious massacre in 1920, prior to Irish independence, when British forces fired into the crowd during a Gaelic football match.
Players and spectators were killed - 14 in all. One of the impressive modern stands, the Hogan Stand, is named after Michael Hogan, a player killed on what became known as "Bloody Sunday".
More than 80 years later, many who opposed the opening up of Croke Park will shudder at the prospect of God Save The Queen echoing round the stadium.
Feelings are running high: radio phone-ins and newspapers have this week debated whether the anthem should be played before the match.
A group of Irish republicans say they will be demonstrating outside the stadium.
The singing of the English national anthem is a sensitive issue
Not so long ago, the idea of the UK Secretary of State for Northern Ireland, Peter Hain, attending a match at Croke Park would have been unthinkable.
But Mr Hain will be there, and at one point there was even talk of him commemorating those who died on Bloody Sunday.
That will not happen. But Mr Hain said: "Above all, this is a sporting occasion between two great friends and rivals. May the best team win."
Many commentators have suggested that this game at Croke Park is a significant symbol of Ireland's transformation.
Bertie Ahern, the Irish Taoiseach (prime minister), said that it would not have happened during the Troubles in Northern Ireland.
As such, after years of the peace process, it is a sign of changed times, although the debate over welcoming in the rugby and soccer teams caused division.
Some argued that it was a mistake to open up the bastion of what are amateur sports to wealthy, professional games which are competing for the attention of Irish young people. Others believed it was time to show the 82,000-capacity stadium to the wider world.
Which brings us to Conor O'Shea's speech to Jonny Wilkinson and his colleagues.
The RFU, aware of the sensitivities involved, wants to avoid any repeat of the type of incident at the 2003 Ireland-England game at Lansdowne Road.
Then, the England team refused to stand on the allotted spot to meet Irish President Mary McAleese, and she was forced to walk across the grass to meet the players. A bit of gamesmanship turned into a fully-fledged row.
With the weight of expectation - and possibly history - on their shoulders against France two weeks ago, Ireland's players struggled.
Now, they and their fans are even more determined to put one over on their old rivals. England cannot say they haven't been warned. The noise of the Croke Park crowd may well be heard across the Irish Sea.