Novelist Jamal Mahjoub’s mother had a comfortable, middle-class English upbringing. His father was from Sudan; “born in a house of mud bricks”, he “received only a rudimentary education”. They met in London and married in 1955, breaking “centuries of taboo”: a black man marrying a white woman.

Mahjoub grew up in his father’s city of Khartoum, which, like the rest of Sudan, “is not one city at all, but fractured”. Built at the confluence of the Blue and White Niles, it is split into three. “This multiplicity hangs over the city as a stark reminder of the country’s nature: diversity, plurality and the potential of unity.”

In 1989 Mahjoub and his parents fled the city they loved after Omar al-Bashir came to power in a coup, but Khartoum has always played a key role in Mahjoub’s fiction: “It was here that I learned about the world and the word.”

This book describes his attempts to rediscover the city of his youth, prompted in part by his “anger and outrage” at the brutal conflict in Darfur and the country’s failure to accept cultural and ethnic diversity. A wonderfully subtle exploration of place, identity and memory that also charts “the tragedy of a nation never achieved”.

• A Line in the River: Khartoum, City of Memory is published by Bloomsbury (£10.99). To order a copy go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £15, online orders only. Phone orders min p&p of £1.99.