This Introduction describes the major currents of change which swept through British writing in the years between 1900 and 1920. It introduces the idea of ‘transition’ as a key concept for the literary culture of the period, and demonstrates its relevance across several domains of life: aesthetic, technological, historical, social, psychological. The Introduction argues that, while major historic movements and events – notably, the rise of modernism and the catastrophe of the First World War – have long been central to our understanding of its literature, we can nonetheless gain a new perspective on the period’s cultural life by viewing it through a wider historical aperture. By charting transitions across the century’s first two decades, the Introduction emphasises the sense of uncertainty and change that characterises much of the period’s most influential and important writing.