Avatar: The Way of Water, the sequel to the highest-grossing movie of all time, has held its world premiere in London.

Its much-delayed launch comes 13 years after the original sci-fi film, which was released in 2009.

Director James Cameron was joined on the blue carpet in Leicester Square by stars Sam Worthington, Zoe Saldaña, Sigourney Weaver and Kate Winslet.

The Avatar series is set on the lush planet of Pandora where the existence of the Na’vi people is under threat.

Speaking at the premiere, Weaver said the film has the “family” as the central theme over the environment as it is more “universal and relatable”.

“It was a joy to be part of that family, we were at each other’s throats sometimes, Jim [Cameron] wanted that… for us to kind of get at each other, still have fun and it’s very much a real family,” she said.

Here are some pictures from Tuesday’s world premiere in London, and you can find more information about the film further down.

Avatar: The Way of Water world premiered in London
Actress Zoe Saldaña, who also starred in the original film, reprises her role in Avatar: The Way of Water
Avatar: The Way of Water world premiered in London
Actor Sam Worthington, pictured with wife Laura, also returns to the franchise for the Avatar sequel
Avatar: The Way of Water world premiered in London
Director James Cameron, pictured with his wife Suzy Amis, plans a further three sequels after this one
Avatar: The Way of Water world premiered in London
Actress Sigourney Weaver was also among the stars seen at the film’s world premiere in London’s Leicester Square
Avatar: The Way of Water world premiered in London
Actress Bailey Bass has joined the cast to play Tsireya, a young Na’vi from the Metkayina clan
Avatar: The Way of Water world premiered in London
Other stars seen on the blue carpet included Black Eyed Peas frontman will.i.am
Avatar: The Way of Water world premiered in London
The famous faces also included Star Wars actor John Boyega
Avatar: The Way of Water world premiered in London
Model Jourdan Dunn was also seen posing for photographers ahead of the film’s premiere

Here are the answers to some burning questions earthlings may have about Avatar: The Way of Water.

What’s the story?

Avatar: The Way of Water world premiered in London
The character Jake Sully (Worthington) seen with one of his children

The first film followed a paralysed marine Jake Sully (played by Worthington) as he travelled to the planet of Pandora, where he took on an avatar body.

He ended up joining the planet’s indigenous population in fighting an attempt by humans to destroy their home to obtain a precious mineral.

The Way of Water is set many years later. Jake now has a family with Neytiri (Saldaña), and it follows their new life on Pandora.

When was it originally due to be released?

In 2010, a year after the original Avatar, 20th Century Fox (as the company was then called, before it was sold to Disney) said there would be two sequels, and that the first of those would be released in December 2014.

That target proved to be somewhat ambitious. And for the next few years, a regular story out of Hollywood was that the release date had yet again slipped back.

December 2014 became December 2016. Which became December 2017. Which became December 2018. You get the idea. Anyway, it’s finally out next week, Friday 16 December 2022.

Why has it taken so long?

Avatar: The Way of Water world premiered in London
Much of the film takes place in the oceans of planet Pandora

Cameron threw out one version of an Avatar sequel that, after writing it, he decided didn’t deliver.

The Canadian filmmaker also has a life outside cinema, and has spent some time doing deep ocean exploration (although maybe that counts as research for the new film, much of which takes place in and under water).

Cameron also wanted to plot out four sequels. And to take full advantage of new filming developments in the worlds of motion capture and CGI.

How long is it?

Well, it’s not Cameron’s longest film. That honour goes to Titanic, which clocks in at a hefty 3hrs 15mins.

But Avatar: The Way of Water isn’t too far behind. Avatar 2, as it may otherwise be called, has a running time of approximately 3hrs and 12mins.

Slightly less if you dive out at the start of the lengthy end credits!