Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Rugby union is the national sport of Wales and is considered a large part of national culture. 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 and is slated to include Italian teams in 2010 11. Top-level Welsh teams also compete in the Europe-wide Heineken Cup and European Challenge Cup and alongside the teams of England''s Guinness Premiership in the Anglo-Welsh Cup. Walesalso competes as one of the 12 "core teams" in the annual IRB Sevens World Series, and won the 2009 Rugby World Cup Sevens.