Yaya Toure's decision to join centre-half and skipper Kolo at the club means they will become the first brothers to play for City since Shaun and Bradley Wright-Phillips.
The Ivory Coast midfielder is just back from the World Cup, where he played every game and scored once for the Elephants in their unsuccessful bid to make the group stages.
Standing at 6ft 2in, the 27-year-old has been a popular figure among Barca fans and had attracted interest from a number of top clubs in the Premier League and around Europe.
Ultimately, however, he chose to make it a family affair with the Blues, and after a short break, he is likely to join his new team-mates at some point on the US tour.
Yaya, one of three footballing brothers, began his career as a youth with Ivorian side ASEC Mimosas in 1996 before he moved to Beveren aged 18 in 2001, spending two full seasons with the Belgian side before joining Ukrainian side Metalurg Donetsk in 2003.
After further spells with Olympiakos and Monaco enhanced his reputation yet further, Yaya became the first Ivorian to be signed by Barcelona who paid around £9m for his services in 2007.
In 2009, he won the Champions League with the Catalans as an emergency centre-half and he celebrated his second successive La Liga title with Barca last May before jetting off to South Africa – his second World Cup having been part of the 2006 squad in Germany.
Leaving the Nou Camp was no easy decision, even to join a club such as City, but Toure packed a Champions League medal and FIFA Club World Cup medal (2009). He also won La Liga twice (2008-9, 2009-10), the UEFA Super Cup (2009), and the Copa del Rey (2008-9).
After 118 appearances with the Spanish giants and almost 300 career appearances to date, City have signed one of the best holding midfielders in the world.
The 49-times capped Yaya wore the No.24 shirt for Barca in honour of one of his boyhood idols, Patrick Vieira. He may have a battle for the same squad number at City – the Blues’ current No.24 is none other than Vieira himself!