Lewis Hamilton's move to Ferrari is the single biggest storyline of the 2025 Formula 1 season.

The sport's biggest star - the only driver who truly transcends the sport - has joined its most iconic team, and interest in how their partnership develops is stratospheric.

These are the key questions as Hamilton begins his new adventure.

Hamilton signed with Ferrari in January 2024, just over six months after sealing a new contract with Mercedes.

It was the talks over that new Mercedes deal that led to the Ferrari move.

Mercedes wanted to offer Hamilton only a one-year contract - team boss Toto Wolff was planning for the future. The seven-time world champion knew he wanted to stay in F1 longer.

They compromised on what is known as a "one-plus-one" contract - a firm deal for 2024 with an option for 2025.

But Mercedes' reticence to commit to him led Hamilton to consider his future. He had always had a hankering after driving for Ferrari and he has a close relationship with their team boss Frederic Vasseur, which dates back 20 years to their time in the junior categories together.

Hamilton's single biggest ambition is to win the record eighth title of which he feels he was robbed by race director Michael Masi making up the rules and mishandling a late safety-car period in the 2021 title decider in Abu Dhabi.

Mercedes had not furnished him with a car in which he could do that since, so he had plenty of doubts on that front, too.

Hamilton approached Ferrari and the team were keen to do a deal. So when they offered him a longer contract - at least to the end of 2026 - and a close to 50% pay rise to a reputed salary of 65m euros (£55m), it was a no-brainer.

The fact that Ferrari had finished 2023 in stronger shape than Mercedes made the decision even easier.

In 2024, Hamilton was comprehensively out-qualified by a team-mate for the first time in his career, ending the season 19-5 down to George Russell in their one-lap head-to-head, at an average deficit of 0.171 seconds.

Although both won two races, Hamilton finished 22 points adrift in the championship.

It was a confusing situation, because in 2022 and 2023, the two had been closely matched in qualifying, and one of them finished ahead in the championship one year and the other the other.

The bottom line is that Hamilton struggled with the characteristics of the 2024 Mercedes more than Russell.

The car had slow-corner understeer. The way to counteract this was to slide the rear on entry to promote turn-in. But doing that generates rear tyre temperature, which reduces grip, a problem that increases over time. Hamilton was less able to deal with this than Russell.

On top of this, there is no question that, frustrated by his qualifying deficit, Hamilton would sometimes push too hard when it mattered right at the end of qualifying. That led to mistakes, which further harmed his performance.

The Mercedes engineers felt that there was something about the general characteristics of the current generation of cars and their ground-effect design philosophy that does not marry as well with Hamilton's style as the previous generations of cars.

But just because that was the case last year does not mean it will be the same this year at Ferrari. It may depend on how the car behaves.

Equally, it's impossible to know how much of an effect psychology had - Hamilton had to do a whole year with Mercedes, the longest season in history, knowing he was leaving at the end of the season, and with his heart effectively already elsewhere.

Certainly Vasseur believes that is too important to ignore. And Hamilton is of the same opinion.

Hamilton turned 40 in January and is the second oldest driver in F1.

Of course, athletic performance declines over time, but Fernando Alonso - who is three and a half years older than Hamilton - insists his age is not a problem, and there is no evidence in his case that it is.

Alonso is still performing at an extremely high level, and produced some outstanding drives last year - as he did in 2023, when again he was older than Hamilton is now.

There is no evidence or reason to suggest Hamilton's age will have a deleterious effect on him.

Hamilton does not speak Italian. He is trying to learn, but it is unlikely the fact he cannot speak the language will have a serious effect on him.

For a start, all technical debriefs in Ferrari are conducted in English. Vasseur also does not speak Italian.

Michael Schumacher could not speak Italian - and he won five world titles with Ferrari and is their most successful driver. Neither could Nigel Mansell. He won on his debut with Ferrari, at the 1989 Brazilian Grand Prix. He became a folk hero in his two years with the team and is still idolised as 'Il Leone' (the Lion) now.

Vasseur says: "You know that 99% of the job is in English. It's good to speak a little bit of Italian for the mechanics and the relationship in the team but I am not sure it is crucial for the performance."

Hamilton's partner/rival in the other Ferrari is Charles Leclerc, a 27-year-old from Monaco who has won eight grands prix and set 26 pole positions since joining the team in 2019.

Leclerc is a Ferrari protege - he has been nurtured by the team since he was a teenager. He is richly talented and regarded as possibly the fastest driver over one lap in F1 at the moment, and his career statistics back that up.

Leclerc does not have such a big offset between his qualifying and race success stats because he is bad at racing. He has it because his ability and raw speed has often meant he has qualified the car higher than its competitive level can sustain over a race distance.

Hamilton is also a brilliant qualifier - he holds the all-time record for pole positions. And in many ways the two drivers are very similar. Both of them have an ability to produce 'wow' performances in qualifying - laps that leave people open-mouthed, thinking, 'where did that come from?'

Hamilton might have to accept that there is a strong chance he will be out-qualified by Leclerc over the season. But he will be confident that what he probably considers his greater race-craft and experience will see him through over a season.

He says: "Charles is very professional, very embedded in this team. He is very fast and I am completely aware of that. You have seen his qualifying laps.

"I told him in Bahrain many years ago (in 2019) he had a bright future ahead of him. It is not going to be easy to beat him. Especially in his home. But we will work together and have some great races, I hope."

Hamilton cannot control whether Ferrari build him a competitive car. And if they don't, the minimum that could be considered success would be to come out on top against Leclerc.

But Hamilton has not gone to Ferrari to score a few podium finishes. He wants an eighth world title. He's confident he and the team can do it. And given his level of career success, and Ferrari's history in F1, nothing less than a championship will suffice.

He says: "This team already has an insane legacy and are not short of championships they have won. They have a winning mentality in their DNA.

"The competition is fierce. It is going to be close. but I have a great team-mate, the energy I have seen from the team, there is magic here.

"It is going to take a lot of hard work and everyone is putting that in. But it is also about belief. Everyone in this team dreams of winning with Ferrari.

"I have worked with two title-winning teams before, I know what one looks and feels like. The passion is like nothing you have ever seen. They have got everything they need to win a championship. It is just about putting the pieces together."