Beauden Barrett is moving to Auckland - and will don the Blues jersey from mid-2020 in a new four-year New Zealand Rugby deal.
Barrett today confirmed he would stay with the All Blacks and NZR until the 2023 World Cup - and move from the Hurricanes to the Blues to play Super Rugby from 2020.
Barrett, 28, has played 73 Tests for the All Blacks since making his debut in 2012 and 125 times for the Hurricanes since his Super Rugby debut in 2011.
As part of his new contract, he will take an extended break away from the game at the end of this year and start with the Blues midway through next year's Super season. He also has an option to take a short playing break in Japan some time over the next four years, with any break to be negotiated with NZR and the Blues.
Barrett said he was "stoked".
"This is obviously a massive decision for me and my wife Hannah and we're really looking forward to the next chapter of our lives.
"The Hurricanes will always be a huge part of who I am. The Hurricanes environment and style of rugby they play has helped me become the player I am today, and I'll be leaving some very good mates.
"Wellington has been my rugby base for many years and university base for Hannah and we'll always have fond memories of living there. Home for us now is Taranaki and Auckland and home and family are immensely important to both of us.
"I'm also enthusiastic about the new challenge I'll get with the Blues over the next four years. They're a team on the rise, I like the way they play and I'm really looking forward to being a part of that.
"While I'm looking forward to what the future holds, right now my focus is on the international season ahead with the All Blacks."
All Blacks coach Steve Hansen said the news was "fantastic".
"He's one of the best players in the world, a leader in our team and has been involved in numerous successful campaigns, from Rugby World Cups to Bledisloe Cups, and I believe he's going to get even better.
"Knowing he will be here through to the 2023 Rugby World Cup is massive for the All Blacks as they move into a new phase post-2019."
Blues chief executive Michael Redman said the signing of Barrett continued the rebuild of the club that began "some years ago" and which had accelerated in the last 12 months.
"Signing a player of Beauden's calibre has been years in the making," Redman said.
"While Beauden's personal circumstances created this opportunity, changes we've made to our club in recent years meant for the first time the Blues were a credible option for him. The process has been long and complex, but we believe the outcome is the most influential player movement in Super Rugby history."
Blues head coach Leon MacDonald said: "I am sure he will be an immediate fan favourite at Eden Park."
Auckland Mayor Phil Goff was also cock-a-hoop at the news.
"It is fantastic news for the Blues. The Blues have a lot of talent but have been under-performing for a number of years," said Goff, a born and bred Aucklander.
"It is time for Auckland, with 35 per cent of the population, to get back to the top of the Super Rugby table."
Barrett and his wife, Hannah, are upping sticks from the capital later this year to base themselves in Auckland.
Barrett, whose father played for the Hurricanes, has been fiercely loyal to the club he first played for in 2011.
The star All Black is understood to be planning to take both a non-playing and playing sabbatical as part of a four-year contract extension to stay in New Zealand.
Goff said Barrett, who has played eight seasons for the Hurricanes and headed north on a four-year contract with the Blues, was a superb player who could help bring out the talent in the franchise.
"I can remember when the Blues were regularly top of the Super Rugby table, but there have been a few dark years and it's time to turn this around. This will help," Goff said.
The mayor also hopes Barrett's signing will attract more fans to Eden Park, which is struggling financially and received a $63 million bailout from the council in March.
Goff, who condemned the rescue package on the grounds it contained a $9.8m grant and not an interest-free loan secured against the assets of the park, said the Eden Park Trust has traditionally stood on its own two feet.
The sooner that happens, the better, he said.
Goff's main rival at October's local body elections, John Tamihere, said Barrett's undoubted quality will be greatly appreciated and help direct some quality players around the park.
"For a city this size, the Blues should be at the top of the table," he said.