When the actor, writer and director Gbolahan Obisesan was growing up in Nigeria, his older cousin would tell him stories. “Whether they were Nigerian fables or Aesop’s fables, she would take on the personas of all the characters,” he remembers, “and wrap our imagination in her ability to do that.” Something similar happens in Obisesan’s adaptation of Chigozie Obioma’s Booker-shortlisted novel The Fishermen, an Edinburgh fringe hit for two years running and now at London’s Trafalgar Studios.

Obioma’s novel looks at the tragedy one Nigerian family experiences after a chilling, violent prophecy. Obisesan and the director Jack McNamara determined to find the best way to tell “the journey of these four brothers and what happened to them. We went through different iterations of considering having four brothers, considering having the parents on stage, considering having two brothers and their mother … Eventually, we decided it needed to be two actors playing all the roles, as a sort of memory play.”

Obisesan is now directing another adaptation of a popular novel – this time, Steve Waters’ version of The Last King of Scotland, based on Giles Foden’s novel, at the Crucible in Sheffield. “It’s tricky,” he reflects, “because books take different forms, and also the story within them. When you’re adapting something, you have to consider whether you’re pursuing a clearly dramatic sort of stage adaptation, for the story to live, or something that feels more in keeping with the artistic choices in the book.”

Facebook Twitter Pinterest Tobi Bamtefa in rehearsals for The Last King of Scotland. Photograph: Helen Murray

The Last King of Scotland looks at the regime of Ugandan president Idi Amin (played by Tobi Bamtefa) through the eyes of his Scottish doctor Nicholas Garrigan (played by Daniel Portman). Based loosely on Bob Astles, a British soldier who became a close associate of Amin, Garrigan is ultimately fictional – but the brutalities of Ugandan life at the time are not. “Wherever he is, we see the story of Uganda, the experience of Idi being in power and the spiralling descent of Ugandan social, economic and general stability.”

Obisesan worked as a dramaturg with Waters on different versions of the script, and they made the decision to use “a chorus of journalists” who help shine a light “on some of the outsider perspectives, as well as tie some of the historical milestones and bullet headings with regards to what’s happening in Uganda, and what various bias newspaper agendas are. Whether it’s a Ugandan press, a British press or an American global press representative, they all have a different understanding of what’s happening, as well as different pressures, and different slants on how to present their information. Hopefully, that comes across as a way to anchor us throughout Idi’s eight-year reign.”

Obisesan is a busy man. This year he has already directed Yvette, Urielle Klein-Mekongo’s one-woman gig-theatre show at the Bush in west London, and debbie tucker green’s random, the story of a black schoolboy and how he and his family are touched by knife crime, for Leeds Playhouse. This year also saw SS Mendi: Dancing the Death Drill, a moving ensemble piece that Obisesan adapted last year for South African company Isango Ensemble, visit the Royal Opera House. This time last year, he was starring as Martin Luther King in a UK tour of Katori Hall’s The Mountaintop. But acting has gone on the back burner.

“I think it’s definitely harder to pursue now,” he says, “because it’s a really competitive field.” Within the industry, he feels “I’m recognised more as a writer-director, and that feels very kind of narrow-minded. I’m not comparing my talents to someone like Simon McBurney or even Kenneth Branagh, but these people [can say], ‘I’m a writer. I’m a director. I’m an actor.’ It’s great to see someone like Michelle Terry running the Globe, or know that Clint Dyer is going to be directing a play that he’s written with Roy Williams [Death of England at the National theatre], because I think that just broadens the industry’s perspective.” Writing, directing and acting are “all in me”, he says. “They’re all very present. The responsibility’s different, but you’re still a storyteller. You still have to give the story to the people.”

After leaving Nigeria at the age of nine, Obisesan grew up in Bermondsey before his family moved down the road to New Cross. Becoming interested in drama at school, he auditioned for the National Youth Theatre as an actor. Writing and directing came after that. “My first play, a really bad play, was called Roadside. It was part of an initiative that the NYT started, where they asked for ex and current members to write a play.” He directed it only because he felt he knew the world of his plays in a way that many of his peers did not. “Although there were a lot of young people from all these different parts of Britain, there were very few young people from inner-city estates, so I felt it was my responsibility to take my play and make sure that it was executed to the best understanding of those environments. Then I was asked to assist on something at Soho theatre, and that’s when I was : ‘Maybe I should pursue directing intentionally, as well as writing.’”

Obisesan still lives in south-east London. Does he feel like where he grew up influenced his work? He pauses for a while. “I used to go to church and walk past all the Millwall supporters, and those sort of environments teach you a lot about how to navigate the world around you. I still draw on them to give me an indication of people’s behaviour as much as also what lies behind the eyes, so to speak.” So he’s a people-watcher? “A little bit, yeah. Definitely. I definitely observed more than I spoke, and I still feel as if I do that. I think, perhaps, I find my opportunities to be outspoken in the work that I make, rather than responding always in the moment.”