The transatlantic slave trade conjures up brutal images of slaves shackled in horrific conditions in the holds of sailing ships and terrible tyranny and back-breaking labour in the plantations of the American South.
For Canadian writer Lawrence Hill, this is all part of a much wider history, a series of migrations of Africans that he likens to a "global milk run", across the Atlantic to the Americas, Europe and even back to Africa.
Hill, 51, from Burlington, Ontario, is the winner of this year's Commonwealth Writers Prize for his third novel, Someone Knows My Name, the story of an African woman whose life encapsulates these amazing journeys.
Aminata Diallo's childhood is shattered when she is abducted from her home in Mali by slave traders. She and fellow captives are force-marched for hundreds of miles to the coast. They are held like animals at a slave trading post, then crammed into a ship for export across the Atlantic.
The crossing is the first and most brutal of a series of journeys throughout Aminata's life, from Africa to the Carolinas, where she is sold as a slave for an indigo plantation, then to New York where she manages to escape to a precarious freedom.
There, her life takes an even more dramatic twist as she becomes part of the Black Loyalists to the British during the American Revolution, and promised a new future with land in Canada. But they are dumped in Nova Scotia and left to fend for themselves.
Aminata then joins a voluntary exodus, funded by the British, to set up the colony of Freetown in Sierra Leone and eventually ends up in London, adopted by the abolitionist cause.
Someone Knows My Name is the astonishing story of a woman, who, in the opening words of the book, seems "to have trouble dying". Along the way she learns to read and write and survives on her learning, wit and skill as a midwife.
The character of Aminata is, of course, 100 per cent fictional, says Hill, on the phone from Sydney, where he is promoting the novel. But her incredible story is entirely possible, according to his research into the history of the slave trade. Through Aminata's life, Hill aimed to unite the experiences of blacks caught up in the "milk run" of 18th and 19th century African migrations. But the heart of the story is close to home.
The history of the Black Loyalists in Nova Scotia is a little-known episode in Canadian history, he says. And the novel, which became a national best-seller in Canada, challenged the notion that the country had always been a haven for slaves seeking freedom. "I think one of the unfortunate national narratives of Canadians is we like to define ourselves as being morally superior to those nasty Americans south of the border.
The fact of the matter is that slavery existed in Canada. And segregation was rampant in major Canadian cities," Hill says.
"The Black Loyalists were treated so abysmally in Nova Scotia that one-third of them voted with their feet and left on a voluntary migration, funded by the British, to have them create a colony of Freetown in Sierra Leone. The number of Canadians who are aware of this - apart from academics and historians, and the descendants [of the loyalists] - you could count on your fingers and toes."
Hill didn't learn of the story himself until the 1980s, when he came across it in a history book he borrowed from his parents. He is the son of a black father and a white mother, civil rights activists and historians, who themselves immigrated to Canada from the United States. For the journalist turned full-time author, its fictional potential was instantly apparent. "I immediately started imagining a woman on one of those ships sailing out of the Halifax harbour, going not just to Africa but back [to Africa]," says Hill.
"Many people have written about the transatlantic slave trade, about the abduction of Africans, the selling of slaves in American markets. This was the first incidence of an exodus of people of African origin back to Africa in the history of the world. It was an untold story for average Canadians and irresistible to a writer."
Another area which was a "black hole" for many people, including Hill, was how "millions of Africans got to the coast. They weren't standing on the sand, waving to the ships to pick them up.
"What I was astounded to learn about was how Africans moved to the coast from the interior, some walking for months, for hundreds of miles far inland to the sea. And they were captured by fellow Africans, it's a hideously distressing but incontrovertible fact.
Europeans hadn't penetrated into the interior, so they had to bribe African intermediaries to bring the 'human product'." The book's original title, and its title in Canada, is The Book of Negroes, after a historical document which records the names of the Loyalists and such uncomplimentary physical descriptions as "stout wench".
In the novel, Aminata is recruited to actually write this record. But the American publishers decided to change the title, says Hill, because they felt the word "negro", which is now a derogatory term in urban America, would alienate African-American readers. There was no question his protagonist had to be a woman, says Hill, because he wanted to tell the story from the point of view of someone who had the most to lose.
Getting inside a woman's head wasn't too difficult, says the father of five. "It doesn't hurt that I have four daughters and a wife. I had many strong African-American women around me when I was growing up." A midwife he met while doing voluntary work in Mali was also inspiration for the character.
"But it was really hard to find her voice, particularly as an older woman. I wanted it to be wry, have humour, not be too serious, but with a quality of looking back to it - once I found her voice as an old woman, the rest fell into place. But I had to write it over and over, like a kid building and knocking over sandcastles.
"I was terrified it would be terrible, that I would be pilloried. But I also felt liberated, writing about a person I couldn't hope to be.
I feel the characters I have created in various books who are completely removed from me, the further away I get from myself, the more interesting characters get." The book took five years to write, a period which seemed "ridiculously long" at the time but in retrospect was a vital time for his story to reach maturation, he says.
Writing about the horrors of slavery was harrowing and caused some nightmares, and was a difficult balancing act between not glossing over the truth and the needs of the story. "The challenge in writing about atrocity and pain, is you can't write it to the point where the readers wonder why they are putting themselves through it.
The trick is to let in enough shafts of light, so there is hope Aminata will be able to salvage something in her life, hope she will still find something she is able to enjoy."
* Someone Knows My Name (Fourth Estate $34.99)