It's been labelled a "tectonic shift", set to shake up the world of rugby union, but what is the Nations Championship - and how will it revolutionise the game? Here's all you need to know…
The Nations Championship is World Rugby's new 12-team tournament that pits the giants of northern and southern hemisphere rugby against each other on a more consistent basis.
The tournament is designed to align northern and southern hemisphere rugby calendars, guaranteeing high-profile fixtures to add more structure and meaning to the existing international windows between World Cups.
The Six Nations teams - England, France, Ireland, Scotland, Wales and Italy - will take on the four Rugby Championship sides - South Africa, New Zealand, Australia, Argentina (SANZAAR) - with Fiji and Japan also representing the south hemisphere.
The inaugural Nations Championship begins in July 2026.
Subsequent tournaments will be held biennially, in every year that does not feature a men's Rugby World Cup or a British and Irish Lions tour.
Each team will play six matches: three in July in the southern hemisphere and three in November in the northern hemisphere.
Twickenham's Allianz Stadium will then host Finals Weekend from November 27 to 29, where the inaugural champions will be crowned.
Rankings for Finals Weekend will be determined by results from the opening six matches, with each northern hemisphere team playing an additional fixture against the correspondingly ranked southern side.
England will launch their first Nations Championship campaign in South Africa, before facing Fiji and Argentina.
Ireland face Australia, Japan and New Zealand, who host France and Italy in their first two games.
Scotland play Argentina, South Africa and Fiji, with Wales taking on the Springboks after facing Fiji and Argentina.
Six Nations chief executive Tom Harrison believes the Nations Championship will transform rugby, unlocking its value for the benefit of the sport and its fans.
"The Nations Championship has the power to redefine the future of rugby, and the partnership between Six Nations Rugby and SANZAAR signals a tectonic shift in the sport," he said.
"Rugby's strongest nations have collaborated with a clear vision to grow the game, by challenging traditional ways of operating to create a tournament structure with genuine global relevance, which will unlock the true value of the sport.
"The world's biggest and best championships are defined by intense sporting drama, and the Nations Championship will stand alongside these.
"The Finals Weekend will add a totally new dimension for fans, and promises to create an incredible spectacle, crown champions, and act as a catalyst to grow rugby's reach, globally.
"By bringing together the best teams and players in the sport and injecting another layer to the fierce cross-hemisphere rivalries, the Nations Championship will take international rugby to new heights."
You need look no further than Argentina's meteoric rise since joining the Rugby Championship in 2012 to appreciate the scale of opportunity now facing Fiji and Japan.
Fiji have consistently punched above their weight on the world stage, and with regular Test matches against Tier 1 opposition built into the calendar, their potential has no ceiling.
Japan's momentum, which surged during the last decade, may have slowed since hosting the 2019 Rugby World Cup yet their Nations Championship berth offers fresh impetus, reaffirming their status and potential as a true rugby nation.
The overhaul of the summer and autumn international windows has raised concerns about the real-world threat the Nations Championship poses to emerging rugby nations.
Georgia - who are 11th in the World Rankings, above Wales and Japan - have contentiously been overlooked.
World Rugby has guaranteed regular Test matches against Tier 1 opposition to the likes of Georgia, Samoa, Tonga and Uruguay, but the opportunity for Tier 2 nations to develop against the world's best will significantly diminish.
With the sporadic scheduling of fixtures, often against each other, those excluded face the prospect of the gap between themselves and the established Tier 1 nations widening.
Promotion or relegation will also not come into force in the Nations Championship until at least 2030, further strengthening the Tier 2 nations' claims the tournament is a closed shop.
Former All Blacks and current Samoa international Lima Sopoaga labelled the Nations Championship a "slap in the face" that "undermines the spirit of inclusivity that rugby is supposed to stand for."
July 4
New Zealand vs France
Japan vs Italy
South Africa vs England
Australia vs Ireland
Fiji vs Wales
Argentina vs Scotland
July 11
New Zealand vs Italy
Japan vs Ireland
South Africa vs Scotland
Australia vs France
Fiji vs England
Argentina vs Wales
July 18
Japan vs France
Australia vs Italy
South Africa vs Wales
New Zealand vs Ireland
Fiji vs Scotland
Argentina vs England
November 6-8
Ireland vs Argentina
Scotland vs New Zealand
France vs Fiji
Italy vs South Africa
Wales vs Japan
England vs Australia
November 13-15
France vs South Africa
Wales vs New Zealand
Ireland vs Fiji
Italy vs Argentina
England vs Japan
Scotland vs Australia
November 21
England vs New Zealand
Ireland vs South Africa
France vs Argentina
Scotland vs Japan
Italy vs Fiji
Wales vs Australia
Finals Weekend (Twickenham)
November 27
Sixth-place North vs Sixth-place South, Third-place North vs Third-place South
November 28
Fifth-place North vs Fifth-place South, Second-place North vs Second-place South
November 29
Fourth-place North vs Fourth-place South, First-place North vs First-place South
