Actor Forest Whitaker has told the BBC about the intense effort he put in to generate his Oscar-nominated performance as Ugandan dictator Idi Amin in The Last King Of Scotland.
Forest Whitaker has already won a Golden Globe for his performance in the Last King of Scotland.
It charts the fictional relationship between Amin and a young, excited Scottish doctor, played by James McAvoy.
Whitaker is now odds-on to follow it with the best actor Oscar.
The actor went to the extent of learning Swahili for the role - taking him four months to lose the Ugandan accent after filming ended - as well as watching endless hours of footage of Amin's speeches.
He also hung around the market in the capital Kampala, meeting people who knew the dictator.
"Everyone had stories," he told BBC World Service's On Screen programme.
"Many of the people I met had a dual feeling of him in the first place - some had relatives who had been killed during the regime, but there remained the feeling that he had also done certain great things for the country.
"That reconciliation was something that I needed to understand in order to play the character."
Jovial and charismatic
Whitaker's performance has been particularly praised for capturing Amin's mannerisms and voice so much that he gives an utterly convincing performance despite not actually resembling the dictator very much.
"We don't really look alike - I'm three shades lighter than him, 40-50lbs lighter than him, my face structure is different," he said.
"Luckily, I suppose that people felt the spirit of the man came across - and that's great."
The Golden Globes are seen as indicators for the Oscars
Indeed, critics have noted at many points in the film, the man whose regime is estimated to have killed 300,000 people appears as pleasant, entertaining company.
"When I looked at the interviews and some of the documentaries that were made about him, I was struck by that ability he had to be jovial, to bring people in, to be charismatic," Whitaker said.
"That was something I borrowed from the research."
In fact, the film's director, Kevin MacDonald, has said that he feared this more jovial side might dominate, and that Whitaker was not "dark-minded" enough to play Amin.
The actor said that had to find "areas of paranoia, fear and, at times, anger" in his performance, and was grateful that MacDonald moved production to Uganda early to give him time to prepare.
Whitaker added he had come to realise some of the difficulties for Amin, with hostile countries around and other leaders trying to kill him, coupled with his confusion of trying to lead the country with his simple soldier background.
"You can understand how some of these things could have occurred," he added.
Meanwhile, he said that while he was very happy with the talk about a potential Oscar, he did not know what to expect.
"It's always great when people talk well about your work," he added.
"You certainly don't know what will happen after the nominations.
"You just try to live in the positive energy that people seem to be putting out around me and my work - and around this film, because I think that kind of talk helps the film."