The Irelan rugby union team represents both the Republic of Ireland and Northern Ireland in rugby union, a popular sport throughout Ireland although the dominant one only in limited geographical areas. Ireland compete annually in the Six Nations Championship (which they have won ten times outright and of which they have shared the championship eight times) and in the Rugby World Cup every four years where they have been eliminated at the quarter-final stage in all but two competitions (1999 and 2007). They also form a quarter of the British and Irish Lions. Eight former Ireland players have earned induction into the International Rugby Hall of Fame.