TO THOSE of us from beyond the Pale, it's only a river. For anyone reared within, however, it represents a Berlin Wall of sorts. The Liffey, heavy with history and darkened by pollution, flows through the centre of Dublin, splitting the city into north and south. This divide is ancient and symbolic and laden with more horse manure than you'd encounter on a fair to middling day at the races.

Today, the divide shall be bridged in most unusual circumstances. The Southsider will head north, across the flowing river, into the heart of darkness. This represents a radical departure. The occasion is the opening of Croke Park to rugby football, in which Ireland play France this afternoon. The clarion call of The Southsider's national game means that thousands of them will have to make the dangerous foray across the Liffey.

After all, there are only a handful of occasions each year in which The Southsider gets to tog out in his Oirland jersey, turn up the collars, and shout on the goys.

The Southsider views the excursion with trepidation. Do they have SUVs over there? Can you get Heino on tap? Do they really eat their young? All these questions may or may not be answered as The Southsider leaves behind the comforts and safety of the First World and ventures forth.

The inherent dangers of the excursion became apparent last week when it emerged that a number of pubs in Ballsbridge and Donnybrook were laying on buses to take The Southsider to and from the ground. Patrons will have to merely board the bus in familiar territory and will be deposited as near the secure stadium as possible. Afterwards, they will be bussed back within minutes of the fulltime whistle, a move which is expected to minimise casualties.

For those unable to get a coveted seat on the bus, other precautions have been taken. The foray will be brief. Entry and exit will be through the most direct route, and all concerned have pledged not to look any native in the eye. Intensive language training has been conducted at private schools throughout to southside to ready their people in the event of getting lost or attacked. Teachers have reported certain vernacular and pronunciation difficulties, particularly with the term "Alri', bud?"

For, in his infinite ignorance, The Southsider has always regarded north of the river as "skanger country". This perception has historic resonance. The original skangers, the Vikings, settled the north shore in the vicinity of Stoneybatter. Of course, those boys would murder for the Carlsberg but wouldn't know a pint of Heino if it walked up and clattered them on their helmets. Since those days, The Southsider has largely avoided ever having to make the crossing.

Traditionally, all the traffic has been in the other direction. Northsiders such as Bono have fled south at the first opportunity, while retaining romantic notions about their native shore.

At one of U2's Croke Park concerts in 2005, the singer proclaimed, "We're on the northside here, the funky part of town." Bono lives in Dalkey, across the bay from the funky part of town.

If The Southsider has been the subject of caricature in the run-up to the game, he can point the finger of blame at one man.

Paul Howard is the creator of Ross O'Carroll Kelly, the archetypal southsider, who has done much for the cause of The Southsider by advertising his frolics and foibles to the world. O'Carroll Kelly is depicted as a dimwitted, rugby-loving scion of a wealthy Foxrock family, with contempt for those whom he believes inhabit the lower orders, particularly the "skangers" from north of the river.

Howard has found that caricature of The Southsider is increasingly difficult.

"When I'm writing, I think I'm exaggerating it, " he says. "You'd get a gross caricature but then hear a story and realise I'm not exaggerating at all.

"Look at the thing about buses bringing them over to Croke Park and back. That's like something I might make up."

Stories of life imitating art are constantly coming his way. "There's one I heard about a south Dublin school which shall go nameless. A fifth year drove his father's beamer in and parked in the teacher's slot. When the teacher confronted him he just pulled out a platinum credit card and held it in front of the teacher's face for 10 seconds. These people exist!"

In some instances, O'Carroll Kelly appears to be a paragon of modesty. He has, at times, enjoyed driving the family car out to Tallaght and screaming out the window, "Affluence!"

Last year, a teacher rang the offices of the Sunday Tribune complaining about the influence Ross was exerting on his pupils. Three of them had recently driven out to the western suburb and proceeded to throw Euro5 notes out the window.

The Celtic Tiger has also had a role in the proliferation of The Southsider. The geographic area in question has benefited hugely disproportionately from new wealth. As a result, The Southsider, particularly the younger, brasher strain, has multiplied like the Boys from Brazil.

The popularity of fee-paying schools in the area adds further to the homogenisation of The Southsider, who now has less chance in formative years of encountering anybody not cut from the same exacting cloth.

The Southsider, however, is more than just a tool who grew up in the confines of the affluent end of the even postcodes in the capital. He - and she - is a state of mind that is gaining in popularity as affluence accelerates.

"I met a girl last week from Cork. She was young, wasn't in Dublin that long and she was talking in a D4 accent, " Howard says. "I heard another story of two women in Galway recently in a car dealership, fighting over who would get the first SUV of the year there.

"This is no longer just a D4 things.

There's C4s and G4s in the other cities."

The old divide in Dublin is also changing. The Southsider may soon have to give up his moniker, as the rich/poor axis has swivelled from north/south to east/west, where the western suburbs now represent what once the northside did. And so, horror of horrors, The Northsider may soon transmogrify into The Southsider and render the river obsolete.

The most recent manifestation of this was the awarding of a Michelin star to Chapter One, regarded by many as the city's finest restaurant and located on the northside.

Co-owner and celebrity chef Ross Lewis pointed out that his greatest pride in achieving the star was that he did it on the northside where they said it couldn't be done. Lewis, a Corkman. Maybe The Northsider is a state of mind too.

C.V.

Occupation: Junior management trainee in whatever daddy does.
Why in the News: Today, he will make the historic journey across the Liffey to attend the Irish rugby international in the strange and hostile environs of Croke Park.