First published in 2002 by the Planet imprint, with a new edition only 12 months ago courtesy of Seren, Charlotte Williams’ Sugar And Slate has now become the latest title in Penguin’s Black Britain Writing Back series, which with the curatorial help of Bernardine Evaristo seeks to give a greater platform to books by Black authors from the UK.

If removing this one (and Dat’s Love by the late Cardiff writer Leonora Brito, published in the series simultaneously) from the pool of Welsh independent publishing feels a shame, from one angle, the chance to afford greater attention to Sugar And Slate, a wonderful memoir-cum-polemic, certainly makes up for that.

Williams grew up in 1960s Llandudno, the child of a white Welsh mother and Guyanese father (Denis Williams, an artist who later did important work in the archaeological field). The upshots of this mixed heritage are revealed as her life progresses, likewise in Sugar And Slate. Accustomed to treatment ranging from othering to outright racism in her north Wales locale, adulthood divulges to Williams a spectrum of social and ethnic contexts in which to exist. In the 80s, shortly after first encountering the still-nascent Caribbean middle class of London – itself a world away from smalltown Wales – she and her husband move to Guyana, where British origins and lighter skin confers heavy privilege.

The author’s life, as recounted here, has been (culturally) rich and varied, but it is the wit and sagacity that Williams brings to her anecdotes, rather than their content per se, that makes her writing so greatly fulfilling. Early on in Sugar And Slate, she is in Trinidad’s Piarco airport – “the Crewe Junction of the Caribbean” – reflecting on how a conversation with a West Indian stranger invariably reveals some friends-or-family connection, just as with a Welsh one. (“I met the Mighty Sparrow here once,” she adds, excellently.)

The book’s title refers to Guyana and Wales’ lucrative export products – lucrative, mainly, for the merchants and their limited companies. Richard Pennant, 18th-century owner of Penrhyn Castle and a slate empire, is an emblem of exploitation: his Bethesda workforce “the Black slaves to his white supremacy, the real Welsh to his Anglo-Welshness.” This historical class dimension is often applied crudely or uneasily to discussions of race, and I suspect is not an overly fashionable line of thinking in a contemporary sense, but it crystallises Charlotte Williams’ worldview, borne of education and experience alike. I really wish I’d read Sugar And Slate 20 years ago.