Eddie Redmayne has continued his domination of the awards season as he carried off the leading actor Bafta for his performance as Professor Stephen Hawking in The Theory Of Everything.
The industry awards, which attracted stars included Tom Cruise and Keira Knightley, also saw big wins for Richard Linklater's family epic Boyhood and Wes Anderson's The Grand Budapest Hotel.
But it was two towering portrayals of the effect of serious illness that won the coveted leading actor and actress awards with Julianne Moore picking up the latter for her role as a woman struck down by Alzheimer's.
Accepting his award, Redmayne reminded the audience of a previous ceremony when he was unable to hand out an award because he fell ill in "an unfortunate fashion".
He said: "I was lucky enough to come to the Baftas a year or three ago when I was suffering from a severe bout of food poisoning and just as Stephen came on to start announcing the awards I had to bolt through that door there and I proceeded to redecorate the corridor of the Royal Opera House in an incredibly unfortunate fashion. It was one of the worst nights of my life, this is one of the best nights of my life."
Redmayne, who has already won a Golden Globe and Screen Actor's Guild award for the role, dedicated this win to three families - his own, his family on the film and the Hawkings "for their trust in us, their generosity and their kindness".
The biopic, based on a memoir by Professor Hawking's first wife, deals with the onset of motor neurone disease which has left him severely disabled.
The Theory Of Everything started the ceremony with a win when David Beckham presented it with the Bafta for outstanding British film.
Its subject also made an appearance when he arrived on stage with another of the film's stars Felicity Jones.
Hawking, described by Jones as the only man more intelligent than Fry, joked he was also "better looking" before they handed over the Bafta for special visual effects to Interstellar.
Jones herself lost out to Moore for the leading actress award, but the film's writer, Anthony McCarten, won the award for best adapted screenplay.
The Theory Of Everything is widely expected to do well at the Oscars later this month with Redmayne hotly tipped to be named best actor.
Cruise took to the stage to present the Bafta for best film to Boyhood which was filmed with the same cast over more than a decade and follows the life of a boy who grows up in front of the camera.
Its director Richard Linklater was also given the best director award.
Accepting her best actress award, Moore thanked her Scottish relatives who "poured love into me".
The early stages of the event, formally known as the EE British Academy Film Awards, were dominated by The Grand Budapest Hotel which picked awards for original music, production design, costume design and hair and make-up.
Anderson won the award for original screenplay and it was accepted on his behalf by the film's star Ralph Fiennes who read out a letter from the American director who was at another awards in the US.
Reading from the letter, Fiennes said:"I was already most unhappy to miss this event but now I'm actually really angry and resentful that I'm not there and I'm furious. I blame the Directors Guild of America for requiring my presence in Los Angeles where most likely I have already failed to win a different prize."
Boyhood also won the best supporting actress award for Patricia Arquette, while JK Simmons was named best supporting actor for his role as a tyrannical music teacher in Whiplash.
Picking up the award from Reese Witherspoon, he said: "This whole experience has been a gift to me."
Last night's event at the Royal Opera House in Covent Garden, Central London, was opened by rockers Kasabian who came on stage after a brief introduction from Bafta chairman Anne Morrison who thanked the audience on behalf of host Stephen Fry for "coming to his wedding reception".
Fry, who recently tied the knot with Elliott Spencer, is the regular frontman for the biggest night in the UK film industry.
Former Bafta president and filmmaker Lord Attenborough, who died last year, was remembered with tributes from the Duke of Cambridge and Robert Downey Jr.
The Duke described him as "inclusive" and "a leader with a vision" and praised his "passion for nurturing, supporting and developing talent".
He said: "I hope that everyone who watches his films and learns about him as a person will be encouraged to follow his example."
Downey Jr, who played the title role in Attenborough's film Chaplin, said "I'm sad. I miss you Dickie."
The EE Rising Star award, the only Bafta voted for by the public, went to Jack O'Connell, the star of '71 and Unbroken.
Other wins saw the Bafta for best documentary go to Citizenfour which is about whistleblower Edward Snowden, while the award for British short film went to Boogaloo and Graham about two boys growing up in 1970s Belfast and the award for short animation was picked up by The Bigger Picture.
The Grand Budapest Hotel's triumphant trawl of technical awards was halted when Whiplash won the Baftas for editing and sound.
BBC Films, responsible for titles including Philomena, Billy Elliot, Eastern Promises and Last Resort, won the Bafta for outstanding contribution to cinema.
The award for cinematography went to Birdman and was accepted by its star, Michael Keaton, on behalf of Emmanuel Lubezki.
The writer and producer of Pride, about an unlikely alliance between gay activists and striking miners in South Wales, won the Bafta for an outstanding debut by a British writer, director or producer.
Polish drama Ida was named best film not in the English language.