In 1917, two revolutions transformed Russia, and set in motion one of the biggest social and political upheavals of the twentieth century.
The February Revolution began when growing civil unrest and chronic food shortages triggered rioting and strikes in Petrograd (now St Petersburg). The subsequent abdication of Tsar Nicholas II and collapse of interim coalition governments prompted a second revolution in October, led by the Bolshevik party leader, Vladimir Lenin.
From first-hand accounts written by its leading figures to explorations of the human cost of revolution, here are five books that unpick and understand the significance of these seismic events.