 Unlike soccer , Ireland continues to field a single national rugby team and a single association , the Irish Rugby Football Union ( <unk> ) , governs the sport across the island . The Irish rugby team have played in every Rugby World Cup , making the quarter @-@ finals in four of them . Ireland also hosted games during the 1991 and the 1999 Rugby World Cups ( including a quarter @-@ final ) . There are four professional Irish teams ; all four play in the <unk> League ( now called the <unk> <unk> ) and at least three compete for the <unk> Cup . Irish rugby has become increasingly competitive at both the international and provincial levels since the sport went professional in 1994 . During that time , Ulster ( 1999 ) , Munster ( 2006 and 2008 ) and Leinster ( 2009 , 2011 and 2012 ) have won the <unk> Cup . In addition to this , the Irish International side has had increased success in the Six Nations Championship against the other European elite sides . This success , including Triple Crowns in 2004 , 2006 and 2007 , culminated with a clean sweep of victories , known as a Grand Slam , in 2009 . 
