Manchester City have completed the signing of ex-Manchester United striker Carlos Tevez on a five-year deal.
The Argentine, 25, left Old Trafford last month after rejecting their offer of turning his loan spell with them into a permanent switch.
City are believed to have paid Tevez's advisors, who owned his economic rights, £25.5m to sign him.
"City showed me they ambition to be one of the biggest clubs in the world and I was very happy to join," said Tevez.
"They made it an easy decision and I am happy to be here."
Tevez was mobbed by joyous City fans on his arrival at Eastlands.
"It's terrific news," said City boss Mark Hughes. "He's an international of the highest class who possesses all the attributes to help drive us forward.
He is not only outstanding technically but he is a reliable goal scorer
"This is yet another deal that shows the commitment of the owner to make this club the very best it can be."
Tevez, who will wear the number 32 shirt at Eastlands, spent a season with West Ham before joining Manchester United on an extended loan deal in 2007.
United boss Sir Alex Ferguson claimed he had texted Tevez and attempted to speak to the Argentine about staying at Old Trafford but had received no response.
"I was there for two years and Sir Alex never called or sent any text messages in that time," countered Tevez, who also denied any deal with City had been agreed in January 2009.
"The only time he talked to me was after a match against Roma to discuss a situation about going to play for Argentina.
"It doesn't seem that this is the way to treat a player in two years at the club. It doesn't seem there is a line of communication."
But Tevez added: "I would like to thank David Gill (United chief executive), Alex Ferguson and the club's fan base, but this is a new life for me and I am happy to be at Manchester City.
His move to Old Trafford ended a long-running saga following complications with West Ham's registration of the player.
The Premier League has ratified all the paperwork regarding his move to Eastlands having been assured City have sole registration of the striker.
"Money was not the most important thing about my move," continued Tevez.
"I have a coach who wants me and a good fan-base and environment around me. I'm excited about working with Mark Hughes and building a good relationship with him."
Tevez, the only player to win the South American player of the year award three seasons running, won the Olympic gold medal with Argentina in Athens in 2004.
He helped United win successive Premier League titles, becoming a crowd favourite as he scored 34 goals in 99 league and cup starts, and has now targeted helping bring the title to Eastlands.
"The objective is to win the league, that is what we have talked about and I'm here to make my contribution to the cause on a daily basis," he said.
"I'm here to win things and I make that pledge now to my team-mates and our fans.
"I will give everything to help City become one of the biggest and most important clubs in England - and win some trophies.
I have no assurances about my place and must win the respect of my team-mates as I fight to be first choice
"But it is very important to remember that I am just one more player to add to the strength of the squad, one more player working with the coach and my new team-mates to help us win trophies for City."
Tevez will become one of a select band to have joined both Manchester clubs and he could re-visit his former club at the Old Trafford derby on 19 September.
"He is not only outstanding technically but he is a reliable goal scorer and someone who will contribute fully to the team ethic," Hughes added.
"He gives us another exciting, attacking dimension."
Tevez scored 15 goals last season but was often on the bench for key games and was wary of not getting enough first-team football ahead of the 2010 World Cup in South Africa.
However, he rejected suggestions that he had been given guarantees of first-team football at City.
"This will be a very challenging season for me," he said. "I have no assurances about my place and must win the respect of my team-mates as I fight to be first choice.
"Then it is the World Cup next summer. I will work hard to achieve these goals."
Manchester City's summer spending so far has seen them sign striker Roque Santa Cruz from Blackburn for £18m and Aston Villa midfielder Gareth Barry for £12m.
Arsenal striker Emmanuel Adebayor is also in talks over a move to Eastlands.
But a proposed bid for Barcelona striker Samuel Eto'o fell through - even though reports suggested the club was willing to make the Cameroon international the highest-paid player in the world, earning £250,000 per week.
There have also been rumours that Chelsea captain John Terry is on Manchester City's wish-list, although Stamford Bridge boss Carlo Ancelotti insists the England defender is not for sale at any price.