Giles is a journalist, author and historian who has spent most of his career writing for The Guardian and The Economist. He is currently Contributing Editor at The Guardian, specializing in international reportage and political analysis. He is a Fellow of the Cañada Blanch Centre at the London School of Economics and is author of three works of history and non-fiction. He was previously The Guardian's correspondent for Spain, Portugal and the Maghreb for a dozen years. He was also Madrid Correspondent for the The Economist for a decade. He has been a regular current affairs commentator for various Spanish broadcasters, including state-owned TVE television, La Sexta and the country's biggest radio station, Cadena SER, as well as writing for several Spanish newspapers, including El País and El Mundo.
He was co-founder and curator of the Docubeats documentary project at The Guardian and El País. In 2012 he was voted Correspondent of the Year by the Madrid International Press Club.
He has been a guest lecturer on journalism or contemporary Spanish history and participant in seminars at numerous universities, including Oxford, MIT and Stanford. He graduated in Human Sciences (Anthropology) at the University of Oxford in 1984 and has also studied at the Universities of Barcelona and Lisbon.