"Winning the [Champions League] final was key, that was the turning point," Drogba told BBC Radio 5 live.
"We made history together but I think now is the best time to move on."
Torres is the future - Drogba
In a statement on
the club's website,
Drogba said: "I wanted to put an end the speculation and confirm that I am leaving Chelsea."
"It has been a very difficult decision for me to make and I am very proud of what we have achieved, but the time is right for a new challenge for me."
Drogba feels that the Champions League win was a fitting note for his departure.
He added: "As a team we have accomplished so much and have won every single trophy possible.
"Saturday was a very special moment for everyone at the club and for all the fans. I am very proud to have played my part in bringing many trophies to this club, which has been my home for the last eight years.
Didier Drogba's Chelsea record
v Manchester United, August 15, 2004
v Crystal Palace, August 24, 2004
2004-05, 2005-06, 2009-10;
2006-07, 2008-09, 2009-10, 2011-12;
Premier League top goalscorer:
"I would like to take this opportunity to thank everyone at the club, especially Roman Abramovich and my team-mates."
Drogba was one of Jose Mourinho's first signings as Chelsea manager and he has enjoyed a highly successful stint in London.
In-depth interview - Didier Drogba
As well as three Premier League titles, he has won four FA Cups and two League Cups before Saturday's Champions League triumph, scoring nine goals in finals.
He is fourth on the list of Chelsea's all-time goal-scorers with 157 and is also the club's leading scorer in European competition with 34.
Chelsea chief executive Ron Gourlay paid tribute to the striker.
He said: "Didier is undoubtedly a Chelsea legend and will always be part of the Chelsea family. He is certainly leaving on a high after Saturday night.
"Of course Didier has contributed so much to all of Chelsea's recent successes. He has been a consummate professional during his entire time here. As one of the natural leaders in our squad he has been an inspiration to a lot of our younger players.
Drogba's finals goal record
2005 Carling Cup final
- scores in extra-time in 3-2 win over Liverpool.
2007 Carling Cup final
- scores both goals in 2-1 win over Arsenal.
2007 FA Cup final
- scores the only goal in 1-0 win over Man United.
2008 Carling Cup final
- puts Chelsea ahead in 2-1 loss to Spurs.
2009 FA Cup final
- scores equaliser in a 2-1 win over Everton.
2010 FA Cup final
- scores only goal in 1-0 win against Portsmouth.
2012 FA Cup final
- scores Chelsea's second in 2-1 victory against Liverpool.
2012 Champions League final
- his 88th minute header took the game against Bayern into extra-time before he scored the decisive penalty in the shoot-out.
"We have known for some time that this outcome was likely but Didier and the club only made a final decision on that in the last couple of days. For obvious reasons neither Didier nor the club wanted to distract focus away from the Champions League final.
"The talks were amicable all the way through and we wish him all the best for the future."
Former Chelsea striker Tony Cascarino says Drogba's decision to leave the club doesn't come as a huge surprise.
"I think there was a number of reasons why both he and the club didn't pursue it," Cascarino told BBC Radio 5 live.
"Didier had a great two months but he didn't have a great season; he was in and out of the team and wasn't scoring like he did in the latter games of the Premier League and the cup competitions.
"I don't think Chelsea were quite so hot to give a 34-year-old a contract that they felt would be over-paying to him."
BBC Match of the Day host and former England international Gary Lineker wrote on social networking site
"Farewell Didier Drogba. You have enthralled us, occasionally enraged us, but always entertained us. A striking superstar."
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.