Michael Ballack admits 'a circle is complete' after the midfielder finalised a return to Bayer Leverkusen on a two-year contract.
The 33-year-old was released by Chelsea at the end of his contract and has opted for a move back to the Bundesliga.
Wolfsburg had been linked with a bid for Ballack, but the Germany international has accepted the offer of a second stint at Leverkusen.
Ballack previously spent three years with Bayer before leaving for Bayern Munich in 2002 and is looking forward to playing for the club again.
"With my transfer to Bayer Leverkusen a circle is complete," Ballack told the club's official website.
"I had a beautiful and successful time here, on which I like to look back on a lot. That was a factor in my decision.
"But above all the good sporting potential of this young and attractive team were persuasive.
"I am especially looking forward to the great fans, who naturally have been key in my decision to return to Bayer."
Bayer sporting director Rudi Voller is delighted to have signed a player of Ballack's experience, and believes he will help the development of the club's crop of young players.
"With Michael Ballack our team is getting an enormous boost in quality," he said. "Especially our many young players will benefit from his abilities and his experience.
"We did everything to convince Michael. That his preference was for Bayer despite our limited financial possibilities in comparison to the competition, shows his emotional attachment to the club."
Ballack is currently recovering from the ankle injury suffered on his final appearance for Chelsea in the FA Cup final, which ruled him out of the World Cup.