History of rugby union matches between Leinster and Ulster

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Leinster versus Ulster is the oldest fixture in Irish rugby, with the first ever interprovincial match taking place between the sides in 1875.[http://www.irishrugby.ie/irfu/history/archived_team_history.php Archived Team History] IRFU As such, a healthy rivalry has developed between the two provincial rivals.[https://www.bbc.com/news/uk-northern-ireland-47725627 "Thousands flock to Dublin for Leinster v Ulster clash"], BBC, 30 March 2019.

Both provinces combined to provide the squad for the Irish international representative side from the first international match in 1875 until the IRFU was formally founded in 1879, consisting of the formal founding of the Leinster and Ulster branches and the addition of a third provincial side, the Munster branch. Finally a Connacht branch was added in 1885 to complete representation for all four provinces of Ireland.

The Interprovincial Championship did not formally begin until the 1946–47 season. Since then, Leinster and Ulster have played in many high profile games, including League and European Cup finals, with Leinster getting the upper hand on the big occasions thus far.