Yaya Toure claims he rejected offers from other clubs in Europe, Asia and the United States to return to Greek Super League side Olympiakos.
The former Barcelona and Manchester City midfielder Yaya Toure made his name at the Piraeus club in the 2005-2006 season before embarking on his glittering career in Spain and England.
The 35-year-old said in a post on his official website: "It is an honour to be back at Olympiacos! When I left in 2006 I said I would come back and I am delighted to keep my word. I had offers from lots of clubs across Europe, Asia and the USA.
"Ultimately, I made my decision based on the special relationship I have with this incredible club.
"I am as hungry for success now as I was when I first arrived here many years ago and I cannot wait to help the club win the trophies the great fans of Olympiacos deserve.
"It is now time to let my football do the talking once again. Let's do this!"
The Greek league leaders confirmed the move but did not give financial details. Local media said Toure would be paid around €2.5 million ($2.9m) for one season.
Toure was presented on front of his new club's fans on Sunday night, as their team won 5-0 against PAS Giannina.
He was released by City after a limited role last season, bringing an end to eight seasons at the club where he won three Premier League titles, two League Cups and the FA Cup.
Olympiakos were third last season, their lowest finish in 23 years after lifting 20 league titles in 22 years.
They compete in this season's Europa League after beating Burnley 4-2 on aggregate in the playoff round.