Manchester City captain Vincent Kompany will leave the club this summer.
The 33-year-old joined the club in the summer of 2008 and has made 360 appearances.
He signed off with victory in the FA Cup final on Saturday, where City thrashed Watford 6-0 to complete a domestic treble.
Kompany said: "As overwhelming as it is, the time has come for me to go. And what a season to bow out.
"I feel nothing but gratefulness. I am grateful to all those who supported me on a special journey, at a very special club."
The central defender was signed by Mark Hughes from German club Hamburg, days before the Sheikh Mansour takeover.
He became a key figure in the success which followed, and leaves City having won four Premier League titles, two FA Cups and four League Cups.
"I remember the first day, as clear as I see the last. I remember the boundless kindness I received from the people of Manchester," Kompany added.
"I will never forget how all Man City supporters remained loyal to me in good times and especially bad times. Against the odds you have always backed me and inspired me to never give up.
"Sheikh Mansour changed my life and that of all the City fans around the world, for that I am forever grateful. A blue nation has arisen and challenged the established order of things, I find that awesome.
"I cherish the counsel and leadership of a good human being, Khaldoon Al Mubarak. Man City could not be in better hands."
City chairman Khaldoon paid his own tribute to Kompany.
"There have been many important contributors to Manchester City's renaissance, but arguably none are more important than Vincent Kompany," he said.
"He defines the essence of the club. For a decade he has been the lifeblood, the soul, and beating heart of a supremely talented squad.
"A booming voice in the dressing room yet a quiet and measured ambassador off it, Vincent can be as proud of himself as we are of him.
"I am not sure he expected to lift the Premier League trophy on four occasions during his captaincy but he will be remembered and revered whenever this period of unprecedented City success is spoken about by future generations.
"His leadership, intelligence and determination have seen him adapt brilliantly to playing under four different managers and overcome some debilitating injuries. He is a special character who has answered every demand the club has made of him.
"We now look forward to celebrating his testimonial match in September so that we can properly celebrate his City contribution. He will always be part of the City family."
Kompany's City career has been affected by long injury lay-offs which have limited the number of appearances he has made.
He has worked hard to prepare himself for life after football, and in 2018 he obtained a Master of Business Administration (MBA) degree from Manchester Business School.
He also set up the Tackle4MCR homelessness charity alongside the city's mayor Andy Burnham and has said that all proceeds from his testimonial will go towards the cause.
