When did the rugby union Five Nations become the Six Nations Championship?

The Six Nations Championship, starting in 2000, is an annual international rugby union competition between the teams of England, France, Ireland, Italy, Scotland and Wales.

The Six Nations is the successor to the Home Nations Championship (1883–1909 and 1932–39), played between teams from England, Ireland, Scotland and Wales, which was the first international rugby union tournament. With the addition of France, this became the Five Nations Championship (1910–31 and 1947–99), which in turn became the Six Nations Championship with the addition of Italy. The winners of the Six Nations Championship are sometimes unofficially referred to in the media as the European Champions or Northern Hemisphere Champions.

England holds the record for outright wins of the Home Nations, Five Nations and Six Nations tournaments, with 28 titles, although Wales follows closely with 26 outright wins with the addition of 12 shared victories to England's 10. Since the Six Nations era started in 2000, only Italy and Scotland have failed to win the Six Nations title, although Scotland were the last outright winners of the Five Nations.