Like the protagonist of Yorùbá Boy Running, Biyi Bándélé had been running from a young age. At 14, he won a writing competition at school; another award in his 20s, for his radio play script Rain, took him to London in 1990. He hit the ground running there, publishing his first novel, The Man Who Came in from the Back of Beyond, in 1991. This was the beginning of a prolific and multifaceted career that, sadly, came to an end when Bándélé died suddenly in 2022 at the age of 54.

At the time he was putting the finishing touches to his film adaptation of Wole Soyinka’s play Death and the King’s Horseman – a play very much centred on death and redemption and now available on Netflix as Elesin Oba: The King’s Horseman.

The forms of his output were as diverse as his subject matter. He went from writing radio plays to stage plays, then novels and short stories; he then directed films and TV and, towards the end of his life, turned to street photography. Stories about his new home in England sat alongside pieces about the Nigeria he left at a young age. His departure came before the collapse of Nigeria’s education system, before General Sani Abacha’s reign of terror and the death of the environmentalist Ken Saro-Wiwa – before most of the events that would become the topics of a new generation of writers. Because of that his subject matter is more diverse and eclectic, much harder to classify.

What is clear, though, is his penchant for historical subjects – from his stage adaptation of Chinua Achebe’s novel Things Fall Apart, set in precolonial Nigeria, to his film adaptation of Chimamanda Ngozie Adichie’s civil war novel, Half of a Yellow Sun, to his own second world war novel, Burma Boy, in 2007. The latter is one of the few novels by an African author about African soldiers in the second world war, and it shows Bándélé’s growing ambition and confidence as a writer.

Formally, it is both a war story and a bildungsroman – something in the tradition of Ken Saro-Wiwa’s Sozaboy. But what makes it really stand out is the author’s adroit use of farce to capture the tragic realities of war. The 14-year-old protagonist, Ali Banana, is lured by the romance of wearing a military uniform, only to end up in the very unromantic, malaria-infested jungles of India and Burma fighting the Japanese on behalf of the British. Told in the form of a Hausa folk tale, it is a brilliant performance, and most readers saw it as a harbinger of what was to come. But then no more novels followed. His attention turned more and more to film directing; now we know that he was also always working on this posthumous novel, Yorùbá Boy Running.

Here, again, Bándélé is turning to history for inspiration. Like Burma Boy, which drew on Bándélé’s father’s stories, Yorùbá Boy Running was partly inspired by the history of Bándélé’s great-grandfather, who, like his protagonist, Samuel Ajayi Crowther, was formerly enslaved.

At the age of 13, the real-life Crowther was captured with his entire family and most of his village by Fulani slave raiders; taken to the slave barracoons on Eko island, or Lagos, as it was named by Portuguese merchants; and eventually sold off to transatlantic slave traders. The slave ship, bound for Brazil, was captured by British navy boats and Crowther was set free. He was settled in Freetown, Sierra Leone, which was founded for returned enslaved men and women.

The fictional Crowther’s story, as well as the real-life one, is a remarkable saga of perseverance, dedication and triumph over adversity. When his brilliance became apparent to the white missionaries, they recruited him to their ranks. Thus began his inexorable rise – he was running not from the slavers this time, but towards a singular career as a teacher, preacher, linguist, author and abolitionist.

What Bándélé brings to this well-known story is his ability slowly and painstakingly to build his protagonist’s character, not just as the public figure known to every schoolchild in Nigeria – the first black man to be ordained a bishop by the Anglican Church of England, the first African to earn a degree from the University of Oxford – but also as a father, a son, a husband and a citizen. The book paints a vivid picture of an emergent Lagos, with its slave markets and its vibrant Saro (returned slaves) community; its king, Dosunmu, forced by the British to sign a treaty at gunpoint ceding away his kingdom for its “protection”.

Bándélé’s highest achievement, for me, is the opening section of the book, dedicated mostly to recreating life in Crowther’s home town of Òsogùn circa 1821 before tragedy befell it. A drunken and rapacious king surrounded by sycophantic courtiers ensures that the town is ripe for the picking by slave raiders, who soon descend upon it. This section reads almost like a play, with carefully choreographed entrances and exits, lyrical language, a devastating sense of humour and dramatic action. Here, for instance, is an exchange between the king’s man and a haughty emissary from an even haughtier rival king. The emissary’s partner has been taken inside a chamber in the palace and beheaded.

“Ibn Ayuba,” Ibn Saidi said, “where’s Ibn Ayuba?”
“Your brother-emissary,” the akogun told him, “desired a shave.”
“A shave?” Ibn Saidi swallowed hard, his throat suddenly gone dry.
“Yes, a shave,” said the akogun. “Fortunately for him, the royal barber was at hand. He stropped his razor, flicked it this way,” he demonstrated, “and that way; just like his father and his father before him. And right before our very eyes, Ibn Ayuba’s beard was gone … So, unfortunately … was his head.”

The wit and dramatic timing read like something by Wole Soyinka. But one doesn’t come to a posthumous novel for its perfect finish; not all the sections of the book are as polished or as inventive as the opening part. The editors have done a great job of ordering and signposting the different sections with dates and thematic headings, making it easier to follow the sometimes intricate chronology of the narrative. We are lucky and grateful that the author was able to leave us with this bookend to his glorious if truncated career that began long ago in Kafanchan, Nigeria, when he started running towards a distinguished future in faraway London.

• Yorùbá Boy Running by Biyi Bándélé is published by Hamish Hamilton (£18.99). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply