The Rugby League Tri-Nations (known as the Gillette Tri-Nations for sponsorship reasons) was a rugby league tournament involving the top three teams in the sport: Australia, Great Britain and New Zealand. First contested in 1999 (as the Tri-Series), it is a logical continuation of the format originally used for the Rugby League World Cup in which the best teams in the world play in a round-robin tournament leading to a final. The World Cup itself is now contested by a much larger number of nations. In 2009 the competition was replaced by a Four Nations series.