The Trigger is an evocative and ingenious take on the centenary of the outbreak of the First World War. While the big guns among our historians, such as Max Hastings and Margaret MacMillan, battle over the political and economic causes of the conflict, Tim Butcher has chosen to focus on the individual. His book follows the footsteps of Gavrilo Princip, the Bosnian Serb radical who killed Archduke Franz Ferdinand in Sarajevo in June 1914 and so triggered the start of the war.

Butcher, a former war correspondent for the Daily Telegraph, is a bestselling travel writer. His previous books include Blood River, which took him through the Congo, and Chasing the Devil, a journey through Sierra Leone and Liberia.