Ospreys celebrate with the Magners League silverware, Leinster v Ospreys, Magners League Grand Final, RDS, Ballsbridge, Dublin, Ireland, May 29, 2010 © PA Photos
The Magners League is an annual domestic competition featuring the leading sides from Ireland, Scotland and Wales.
Four Irish provinces, four Welsh regions and two Scottish franchises compete on a home and away basis during the regular season with the top four sides qualifying for the semi-final play-offs. The top two sides are guaranteed home advantage with the final staged at a neutral venue.
Launched as the Celtic League in 2001-02, the competition has been dominated by Irish sides who have won the title on five occasions.