Sugar in the Blood: A Family's Story of Slavery and Empire, By Andrea Stuart

Andrea Stuart has written a magisterial work of history. One would expect no less from the prize-winning author of The Rose of Martinique: A Biography of Napoleon's Josephine. But there are particular challenges to overcome and sensibilities to fine-tune when one's own antecedents are the subject matter, and when the balance between casting protagonists as victors or victims is so deeply personal.

Born and raised in the Caribbean and US, and now based in England, Stuart already knew much about migration, acknowledging that her family is one of millions across the globe forged by sugar, slavery and settlement. She set out to explore how those epic forces both shaped ancestral experiences and impact on our world today. She recounts the stomach-lurching moment of discovery in a library of the name of her earliest known ancestor – her maternal grandfather eight times removed. A young Leicestershire blacksmith called George Ashby, he left England in the late 1630s to seek a new life in the colony of Barbados, most easterly of the Caribbean islands.

Stuart traces that European bloodline back to 1620; the book comes graced with family trees, map, notes, bibliography and index – all proper evidence of thorough research. Unfortunately and inevitably, comparable records for the African lineage do not exist.

In tracking the lives of the Ashbys as they become enmeshed in the sugar industry and the Atlantic slave trade, the book really delivers. A four-generational chronicle threads through the bulk of the pages, alongside the story of Barbados: a unique island, first predominantly populated by indentured white labour, then enriching itself by pioneering the cultivation of a crop that came to be known as "white gold", and beginning the importation of what would become millions of enslaved Africans to do the back-breaking work on plantations in the Americas.

As sugar cane flourished and the island's fortunes rose, prospective planters arrived from Britain to claim a share of the bounty. It was not a smooth trajectory, with rebellious slaves, disease and tropical storms to contend with along the way. Women were scarce but Ashby was lucky enough to marry one, a migrant like himself, and they began a family. Against all odds, he progressed from small-farmer to owner of several slaves.

The story of the Ashbys, as of Barbados, is a complex one. It opens up thought-provoking and often disturbing perspectives on class, race, gender, sexuality, property, greed, migration, liberation and much else. Stuart is admirably clear-eyed and unsentimental, rarely using a first-person perspective, relating or surmising from documented facts that are harrowing enough unadorned. I occasionally wished her to be less dispassionate, to make it clear whose side she is on – while being aware that she is, of course, a product of both sides (as indeed am I).

Talking of the sexual relationship between a white planter progenitor and an enslaved black girl, barely out of childhood, Stuart sees evidence of affection and obligation on his part. Yet she knows one can hardly speak of commitment or choice or desire in such an unequal situation - perhaps "the living hell of repeated rape". And she still has patience enough to debate the effect on the planters' wives, who may have "regarded their husband's relationships with slave women as inevitable, but this didn't mean that it didn't upset them." The author's self-imposed pressure to be objective must have been heavy but I would be the first to absolve her.

The book's last section brings a sort of bittersweet catharsis, as Stuart lets us see her place in the narrative. She has to admit: "Most of us do not understand the forces that brought our ancestry together from opposite ends of the world. Nor do we fully acknowledge that these forces continue to shape our communities and our life chances". Breathe a sigh of relief that Sugar in the Blood has not been sidelined into "Black History Month", for it resonates with all our histories – white, black and brown. It is the back-story behind some of the most victoriously British of institutions – whether the grand Tate galleries that draw visitors unmindful that the collections were funded by the exploitative sugar company Tate & Lyle, or the august All Souls College in Oxford, "paid for by the profits generated by the slaves who toiled and died at the Codrington estate in Barbados". This is a family's story of slavery and empire, indeed, and an unforgettable one.