Rugby union is considered to be a huge part of the national culture and is the national sport of Wales. Rugby is thought to have reached Wales in the 1850s, with the national body, the Welsh Rugby Union (WRU) being formed in 1881. The national team play out of the WRU-owned Millennium Stadium, and compete annually in the Six Nations Championship, as well as having competed at every Rugby World Cup. Wales are ranked as a tier-1 nation by the International Rugby Board (IRB). The main domestic competition in Wales is the Magners League, in which Wales have four sides in the competition which is also contested by Irish and Scottish clubs. Welsh teams also compete in the European Heineken Cup and European Challenge Cup. Wales also competes in the IRB 7’s series and in 2009 won the World Championship. Beneath the Magner’s League, club rugby is represented by over 200 WRU affiliated clubs who play in the Welsh Premier Division and the lower Welsh Divisional leagues. Historically the four major Welsh club teams that have shaped the Welsh national team have been Cardiff, Newport, Swansea and Llanelli, though other clubs which have fought for prominence and provided national sporting heroes during the last hundred and twenty years include Bridgend,Neath, Pontypool, Pontypridd, and England exiles London Welsh.