Moxham was born in Evesham, Worcestershire on 13 September 1939 and went to Prince Henry's Grammar School there. In 1961 he went to Nyasaland (now Malawi) to manage a tea plantation. In 1973 he returned to Britain and established a small gallery in Covent Garden to sell African art, travelling widely in Africa. In 1978 he went to Camberwell College of Art and Crafts, where he qualified as a book and archive conservator. Subsequently, he was a conservator at Canterbury Cathedral Archives and then became Senior Conservator at the Senate House Library of the University of London, from which he retired in 2005. He lives in London[when?], travels widely in south and south-east Asia and is a Fellow of the Royal Geographical Society.
Moxham's first book was The Freelander, a novel based on the exploits of a group of idealists trying to establish a commune on Mount Kenya in the 1890s. His best-known book is The Great Hedge of India. This book is part-travelogue, part-historical treatise on the author's quest to find a 1500-mile long customs hedge built by the British in India to prevent smuggling of salt and sugar. His next book, Tea: Addiction, Exploitation and Empire focuses on the effect of British tea addiction on British policies in Asia and Africa, and includes the author's own experience as a tea plantation manager in Africa. An updated edition " A Brief History of Tea" came out in 2009. In 2010 he published a memoir, "Outlaw: India's Bandit Queen and Me" about his friendship with Phoolan Devi, the Indian bandit turned politician. In 2014 he published as an e-book a novel, "The East India Company Wife", based on the real life of Catherine Cooke, a thirteen-year-old English girl who went to India with her parents in 1709. In November 2016 The Theft of India: The European Conquests of India 1498 – 1765 was published.
