Jose Mourinho says he has returned to Chelsea because he wants to leave a long-lasting legacy for the first time in his managerial career.
The 50-year-old Portuguese has achieved success wherever he has coached, but he has never remained with a club longer than the three years and three months he spent at Chelsea in his first spell between 2004 and 2007.
He returns to Stamford Bridge, on a four-year contract, having won a further eight trophies with Inter Milan and Real Madrid, but says he now wants to sow the seeds of long-term success.
"You need stability for identity, and I think identity becomes more important in football," he told reporters after being officially presented to the media on Monday.
"You need stability if you want to go in this profile direction. If Chelsea bought lots of young players, those players need to be developed.
"With Financial Fair Play, and Chelsea wants to go in that direction, you also need stability. You cannot change manager and philosophy every few years.
"It's more difficult to keep trying to win and trying to be successful, while at the same time developing young players while giving an identity to the team.
"But it's something I want at this stage of my career. Titles I have. Money I have. I need challenges."
While Mourinho was at Madrid, Chelsea ended owner Roman Abramovich's nine-year quest for Champions League glory by prevailing over Bayern Munich in the 2012 final.
They followed that up with success in the Europa League under interim coach Rafael Benitez, but Mourinho says the club must aim higher.
"I think Europa League winners can be analysed in two ways: one way, you won it; the other way, why did you win it? Because you didn't get through the group phase of the Champions League," he said.
"The point is we have to prepare ourselves to win, or not to win, but our target level is not Europa League. It's the Champions League and the Premier League."
Mourinho inherits a squad rich with talented young players such as Eden Hazard, Oscar and Victor Moses, but he also faces awkward decisions about how to handle the old guard.
John Terry, in particular, is no longer the first-choice selection he once was, and Mourinho says that, although the 32-year-old centre-back will remain club captain, he cannot guarantee him a role in the team.
"John is the club captain. I'm more than happy with that, so are the fans, so I think he has to be the club captain," Mourinho said.
"With the armband? Only if he plays. If he isn't in the starting XI, he won't have the armband."
Striker Fernando Torres belatedly found his feet at Chelsea under Benitez, scoring 22 times in 64 games, but Mourinho hinted that he may be allowed to leave the club in the close season.
"He's more than happy to stay and work hard, and I think he deserves that respect from me, especially, and also the club," Mourinho said.
"That respect starts by speaking with him face to face and deciding what is the best for all of us. If the best for all of us is for Fernando to stay, let's help him and try and get the best out of him."
Mourinho said he was relishing his return to England and claimed his love of all things English even extends to the much maligned festive period, when Premier League teams must squeeze in match after match while their continental counterparts enjoy a winter break.
"Would I prefer to have a week's holiday in Christmas, like I did in Spain? Where did I go? New York two years ago. Last year, Brazil," he said.
"That's fantastic. But I prefer to play. I was envious watching the Premier League at home. Envy. Total envy. Is it right playing four consecutive matches? Probably not. But I love it."