´óÏó´«Ã½

Acting the big man

´óÏó´«Ã½ Four's new drama sheds light on the marriage of one of the most fascinating couples of the 20th century, the Mandelas. But, for once, the freedom-fighter who was imprisoned for 27 years in Robben Island Prison is not the focus of the story. Instead viewers will watch what happened to Winnie Mandela, the wife he left behind.

David Harewood, who undergoes an incredible physical and vocal transformation to play Mandela in this film, admits that playing an icon was a frightening prospect.

"When I first heard I had got the role I was delighted, then terrified, and I thought, 'how do you play such a hugely mythical, iconic figure?'

"I read as much as I could, I ploughed my way through his autobiography and several other books including Anthony Sampson's biography, which is brilliant, and really just started with the myth and whittled it down to the man."

David admits it was at times a little difficult to be playing this important man as a supporting role.

"I'd go out on set and have to think, 'actually, this isn't about me, even though I want to do loads of stuff, it's about Winnie'. Mentally it was difficult having read all this information but then coming on and playing a supporting role."

He immersed himself in research and his detailed characterisation was sometimes even a little too accurate.

"I pounded away at the treadmill because I'm a pretty big guy and I had to play Nelson young and old, so when I was older I needed to look a bit frail. I don't normally use things like YouTube in my research, but I watched loads of footage of Nelson.

"The voice is something I'm really proud of. Again I listened to his voice on YouTube and on recordings. Actually I almost had it too authentically – because his speech has such a strong pattern I had to back off it; if you have ever heard Mandela speak it can be a bit boring – he writes great speeches but someone like Martin Luther King was a great orator. Mandela is not necessarily a great orator. He's got the repetitive tone, and I nailed that too well because the director said to me, 'you can't spend the whole film speaking like that because it's going to get a bit inexpressive', so I had to bring in some of my own voice, but I'm really happy with the results.

"Normally, when I'm on set, I'm the clown, but this time was the first time I was really concentrated and tried to stay in character all the time, because I felt if I'm playing an old man and I'm dressed like an old man with the wig, I can't walk around like a young man. I'd even walk to the set as Mandela, which was quite slow, so I'd get a lot of quizzical looks from the crew, and it took me a long time to get anywhere."

Despite the difficulties of playing Nelson as a supporting role, David is in no doubt that Winnie's story needs to be told.

"History hasn't been kind to Winnie – she hasn't helped herself, but I think she had a very difficult time. She's an incredible, strong character, and if it wasn't for her people may have forgotten about Nelson. She wouldn't let that happen, but the effort of that, together with some of the physical abuse she received at the hands of the regime, certainly took its toll.

"I also think it's really important for South Africans to remember her story. Whilst we were filming there were members of the crew who had no idea these things happened. One day the sound girl came in having had an argument with her mum, because when she told her what happens in the film her mother said, 'that's all nonsense' – she refused to believe it.

"When I was in South Africa I went for dinner with some friends and I knew more about their history than they did – it just hasn't been told. Even today in the papers it says, 'the dream of a rainbow nation is waning' because racial politics haven't really changed that much, there's still not that much interaction. When I was there I was amazed at how, despite all the wonderful colours, they don't talk to each other, there's blacks here, whites there, Indians here and there's very little interaction – it's not as diverse as London, they all stick to their own groups. You can see that there is still a way to come, so I think films like this are important so people can look at their own history and make judgements from it."

David is also very impressed with leading lady Sophie Okonedo's performance: "She's amazing. I think for the first two days I was in awe of her because she was so real and it threw me a little bit. She's a great actress, probably one of the best actresses I've ever worked with and I thought, 'I've got to up my game here'. She was just a joy to work with – I think it's a fantastic performance."

But both David and the rest of the crew found Sophie, who performed the older Winnie scenes in a fat suit, a little intimidating.

"When Sophie had the fat suit on she was really frightening. Big women in South Africa just carry their weight really proudly and Sophie embodied this fat suit – she was a frightening presence. She also had these things in her mouth to puff out her cheeks – she was a real handful."

David's research led him to try and discover Mandela 'the man' and served to inspire him even further: "People know Mandela the politican, Mandela the President and the prisoner but not many people know Mandela the husband and the father, and I think this film really does tell a different story – the personal story.

"In my research I came across these love letters that he wrote to Winnie from prison and they are just heartbreaking, really beautiful, because he really loved her, but he never got the chance to be her husband, or to be a father to his children, and I hope that what this film does is peel back some of the layers of the myth and show how difficult it would have been to be in that position.

"His own daughter once said, 'I never had a father because when I was young he was in prison and when he was out he was too busy being father of the nation', and he admitted to Winnie that he feels incredibly guilty that he was never able to be her husband. The film suggests that in a way it was better for him, because he was in prison, whereas Winnie was exposed to the rough winds of the apartheid regime and they exacted their revenge on her."

The experience of filming in South Africa was also memorable for David: "It was a very tough shoot, all of it in South Africa, literally a stone's throw from where all of it happened, which was very special.

"I had a crowd scene at one point with lots of extras who were locals and as I addressed them you could see the shock on their faces. At the end they applauded and were saying, 'wow, he sounds just like him'. It was great – they were really genuinely impressed with what Sophie and I had done, that we hadn't come in and tried to play these important historical figures as caricatures – we both embodied the parts."