The Revenant has dominated the Baftas by winning three of the biggest awards including best actor for Leonardo DiCaprio.
The outdoor epic was also named best film, while Alejandro Gonzalez Inarritu received the best director gong.
DiCaprio, 41, hailed the influence of British actors on his career, including Tom Courtenay, Gary Oldman and his co-star Tom Hardy, as he collected his first Bafta.
He also paid tribute to his mother on her birthday and after the ceremony he called Kate Winslet his "home girl".
The American, who is hoping to land his first Oscar later this month, said on stage: "I'm absolutely honoured by this award tonight. I have to say as an actor I've been so influenced by so many British actors throughout the years.
"I want to thank one in particular British actor and that was my partner in this process - Mr Tom Hardy.
"I want to thank you for your fierce loyalty, not only as a collaborator but as a friend. I could not have done this journey without you."
Paying tribute to his mother, he added: "There's one person I have to thank. I would not be standing up here if it weren't for this person.
"I didn't grow up in a life of privilege. I grew up in a very rough neighbourhood in East Los Angeles. And this woman drove me three hours a day to a different school to show me a different opportunity. It's her birthday today - Mom, happy birthday, I love you very much."
DiCaprio beat last year's winner Eddie Redmayne, who was nominated for The Danish Girl, as well as Michael Fassbender, Matt Damon and Bryan Cranston.
Speaking after the ceremony, DiCaprio said he was "shocked and amazed, honoured", adding: "All of this was not expected tonight."
Asked if he was looking forward to winning an Oscar, he said: "This is one thing that is absolutely beyond my control. We did the work, we put our heart and soul into this movie. I can't say we didn't put everything on the table creatively as an entire team in making this movie, so you know, it's up to the world now, and voters to decide."
"But I'm really happy to be a part of a film like this, because I think that it's a genre, the epic sort of art house film is something that is basically becoming extinct in our industry.
"And I think there's an urge from audiences around the world to see something that is like I said poetic and epic and existential and all of those things.
"So I'm just happy that more people are going to hopefully finance films like this in future. That's my hope anyway."
Asked about how he feels about all the support he has received from people wanting him to win an Oscar, including from his Titanic co-star Kate Winslet, he laughed at the idea of the actress being his "main groupie", and added: "It feels amazing, honestly. No, honestly, I have a true love for cinema. I have ever since I was a young teenager.
"I grew up in this industry. Ironically I felt very detached from it even though I lived in East LA, in Hollywood.
"I always felt like it was this distant thing that I couldn't touch. So to have worked in this industry ever since I was 13 years old, having done 20 some odd movies, to be here now, and have it be for a film like this that we've worked so very hard on really feels amazing."
Asked about Winslet, he said: "Kate's my home girl."
Mexican director Inarritu, who won the best director Oscar in 2015 for Birdman, said he was "overwhelmed" and described his Bafta win as "a true honour".
Brie Larson was named best actress for her leading role in claustrophobic drama Room.
The American, who was the overwhelming favourite for the award, was unable to attend the event because she was filming elsewhere.
Collecting the award on her behalf, Room director Lenny Abrahamson said: "Brie, looking for a little bit of something light and nice to do after Room, is wrestling a large gorilla in Australia."
He said she is "incredibly honoured" to receive the award and he described her as "one of the best actors of her generation".
Winslet won the best supporting actress award for her performance in Steve Jobs, the biopic on Apple's co-founder.
Collecting her third Bafta, Winslet, 40, hailed director Danny Boyle as "amazing" to work with and called the film's lead star Fassbender "an extraordinary actor".
She also mentioned her husband Ned Rocknroll, saying: "Hi babe, happy Valentine's day."
Fellow British star Mark Rylance was named best supporting actor for his role as a Russian spy in Bridge Of Spies.
The film's director Steven Spielberg collected the award on his behalf as Rylance is performing in the off-Broadway play Nice Fish.
Presenting the award, Australian actress Rebel Wilson had a dig at the Oscars diversity row.
She said: ''Idris Elba you're making me nervous... I'm sociologically programmed to want chocolate on Valentine's Day.''
In a successful night for The Revenant, the film also received Baftas for cinematography and sound.
Brooklyn, the Irish immigrant drama starring Saoirse Ronan, was named outstanding British film, while Amy took the documentary award.
Asif Kapadia, who directed the documentary which told story of singer Amy Winehouse's life and premature death, said: "We really fell in love with her when making the film. And our aim and mission was really to try and tell the truth about her. To show the world what an amazing person she was, how intelligent, how witty, how beautiful she was, before it all kind of got out of control and went a bit crazy."
Mad Max: Fury Road took the Baftas for editing and make-up and hair while the award for original music went to Ennio Morricone for The Hateful Eight.
Star Wars: The Force Awakens was awarded for special visual effects. Mad Max: Fury Road won the Baftas for costume design and production design.
The award for outstanding British contribution to cinema was given to a British costume supplier which has provided clothes for some of the most successful films in history including Star Wars, Titanic and Lawrence Of Arabia.
Angels Costumes, founded in 1840, has worked with the film industry for more than a century.
Operator took the prize for British short film while Edmond was named as best British short animation. The award for a film not in the English language went to Wild Tales.
The ceremony, hosted by Stephen Fry, was staged at the Royal Opera House in Covent Garden, central London.