Miners' strike drama Pride has been named best film at the British Independent Film Awards.
The film, about an alliance between gay rights campaigners and pit workers during the 1984 strike, collected three awards in total.
Andrew Scott and Imelda Staunton won the best supporting actor and actress prizes for their roles in the film.
Brendan Gleeson was named best actor for Calvary and Gugu Mbatha-Raw won best actress for Belle.
Accepting the top award of the night, Pride director Matthew Warchus said: "We're getting reports from up and down the country of audiences standing up and applauding. That doesn't really happen in British cinemas.
"It's just extraordinary. It's a real tribute to the source material."
Writer Stephen Beresford added that the film had one "simple, compelling message: unite".
"When I was first told the story I was blown away by it - people ask 'is that really true?'
"It took 20 years to convince anyone that a film about vegan lesbian activists was a sure-fire hit."
Northern Ireland thriller '71 went into the awards with nine nominations but only picked up one prize on the night - best director for Yann Demange.
Frank Sidebottom-inspired film Frank won best screenplay for its writers Jon Ronson and Peter Straughan. It also picked up a second award for technical achievement, for its music.
Sameena Jabeen Ahmed was named most promising newcomer for her role in thriller Catch Me Daddy.
"Independent film allows subjects to be approached that are not massive crowd-pullers," Gleeson said, after winning his best actor trophy for Calvary.
"Fantastic films are made in the independent circuit. It's whether people want to pay for something that's going to challenge them," he added.
Iain Forsyth and Jane Pollard won best debut director for Nick Cave film 20,000 Days on Earth and drama The Goob won best achievement in production.
The best documentary award went to sports film Next Goal Wins, while The Karman Line was named best short and the Raindance award went to fantasy drama Luna.
Richard Linklater's Boyhood won best international film. The director accepted the award, giving a "a big shout-out to my friends on table one".
He dedicated the award to If... and This Sporting Life director Lindsay Anderson.
Although he lost out on winning the best actor prize, Benedict Cumberbatch was awarded the Variety award for helping "focus the international spotlight on the UK".
The 38-year-old told the audience: "This award will inspire me to work harder, to make me feel like I deserve it - which won't be difficult, because I love my job."
Oscar-winning actress Emma Thompson was presented with the Richard Harris award for outstanding contribution to British film.
Joking about being given the award by a body honouring independent film, the actress - whose career has included a role in the blockbuster Harry Potter franchise - confessed: "I have taken small roles in big studio films for money, and I am sorry."