In the one hundred years that have passed since July 1914 the origins of the First World War have been continuously contested. This article reviews the debate and takes stock of the recent literature. Its first part outlines how the various explanations for the occurrence of the war came about and sketches the main contentions of these interpretations. The second part of the article considers the historical writing that provides the contextual foundations for the work on the origins of the war itself. The arms races, alliances and foreign policies of the powers involved are outlined and their relevance for the assumptions about the origins of the war is assessed. The article reviews the more prominent recent work on the July crisis in this context and evaluates the contrasting new interpretations. The essay concludes with suggestions as to what is required in further scholarship dealing with the topic.