Pro12

The Pro12 (known as the Guinness Pro12 for sponsorship reasons) (formerly known as the Celtic League, Magners League and RaboDirect Pro12) is an annual rugby union competition involving twelve professional sides from Ireland, Italy, Scotland and Wales. The league is one of the three major professional leagues in Europe (along with the English Premiership and the French Top 14) the most successful teams from which go forward to compete in the European Rugby Champions Cup, the pan European championship which replaced the Heineken Cup after the 2013–14 season.

Beginning in the 2001–02 season, the league was originally known as the Celtic League (Irish: An tSraith Cheilteach; Italian: La Lega Celtica; Scots Gaelic: An Lìog Cheilteach; Welsh: Y Gynghrair Geltaidd) and comprised teams from Ireland, Scotland and Wales. The league was sponsored by Irish cider makers Magners from the 2006–07 season until 2010–11. At the start of the 2010–11 season, the league expanded from ten to twelve teams, adding two Italian teams and following the end of Magners sponsorship the league was sponsored by RaboDirect from 2011–12 through to 2013–14. The "Pro12" was adopted to reflect that it now includes teams from outside the Celtic nations. The current sponsorship deal with Guinness commenced at the beginning of the 2014–15 season.