It’s been almost ten years since the two teams that are one of the most hated rivalries in British soccer last played a league match against each other. On that cold Spring morning in 1999, the Welsh derby between Cardiff City against Swansea City ended in a drab nil-nil draw. Both teams, at the time, were in the bottom division of the Football League.

The two Welsh sides finally play against this each other this Tuesday (September 23, 2008) in the Carling Cup in a game televised live on Sky Sports (and on Setanta in the United States) at 2:30pm ET/7:30pm BST. It’ll definitely be a classic to watch if you’re a fan of the beautiful game.

While the nineties were mostly a dark time for Welsh club football, a lot has changed since then. That season, Cardiff were promoted to League One where they continued their slow ascent into the Championship League. Last season, Cardiff were finalists in the FA Cup Final and came within six points of qualifying for the playoffs.

Forty one miles west of Cardiff, the capital of Wales, Swansea’s fortunes haven’t been as pronounced but a recent resurgence under the leadership of Spaniard Roberto Martinez saw the club break their record of most points in one season (92) when they finished as champions of League One.

Now that Swansea has returned to the Championship League for the first time in 24 years, football fans have three opportunities this season to see why the Welsh derby is one of the most heated battles in the Football League.

Interestingly, the rivalry is more pronounced off the pitch than on it. On the pitch, the match often resembles a Merseyside derby played at a frenetic pace involving plenty of red cards and rough play, but few moments of brilliance or goals.

For me, when I was growing up in Wales until the age of 14, I would go to as many Swansea matches as possible. But in the late 70s and early 80s, the only two matches I would purposefully stay away from was when Swansea’s opponents were either Cardiff or Chelsea.

Off the pitch, the viciousness and hatred between the Cardiff and Swansea fans is the most venomous in all of England and Wales.

After ten years of no league matches against each other, the fear is that violence will rear its ugly head when both teams play each other this Tuesday and on November 30 and April 4. In the past decade, old grudges have had a chance to fester.

One recent incident that will be on the minds of Cardiff fans looking for retribution is the April 2006 Football League Trophy final. After Swansea beat Carlisle at the Millennium Stadium in Cardiff, two Swansea players unfurled a Welsh flag that contained anti-Cardiff insults written on it. To make matters worse, one of the Swansea players wore a T-shirt with an image of a Swansea player urinating on a Cardiff shirt.

Club officials and local police, looking to reduce the likelihood of mass violence, have scheduled the November 30 match between both sides for an eleven thirty kick off on a Sunday morning. A heavy police presence will be on display for the match will be televised live on Sky Sports as the Bluebirds of Cardiff battle the Swans. Expect a very heated atmosphere both inside and out of Swansea’s Liberty Stadium.