Which tournament is the most famous in rugby?

The Six Nations Championship is rugby's oldest international tournament in the Northern Hemisphere, steeped in history and tradition. It began as the Home Nations Championship in 1883, featuring England, Ireland, Scotland, and Wales. France joined in 1910, creating the Five Nations, and Italy completed the lineup in 2000, forming the Six Nations we know today. The tournament is held annually between February and March, and each team plays the other once. Winning all your games is called a "Grand Slam," a feat that adds extra prestige. The intensity of the matches, the rivalries between the nations, and the long history make it the most famous rugby tournament, especially in the UK and Europe. While events like the Super Bowl and Wimbledon are massive sporting events, they aren't specific to rugby. Royal Ascot is a horse racing event, so it has nothing to do with rugby.