Peter Barber, head of Map Collections at the British Library reports for the The Daily Mail ten of the greatest maps that changed the world. The number one listed (above) is Be On Guard! from 1921:
The infant USSR was threatened with invasion, famine and social unrest. To counter this, brilliant designers such as Dimitri Moor were employed to create pro-Bolshevik propaganda.
Using a map of European Russia and its neighbours, Moor's image of a heroic Bolshevik guard defeating the invading 'Whites' helped define the Soviet Union in the Russian popular imagination.
Others include Google Earth, Charles Booth's map of London poverty, and the earliest known Chinese terrestrial globe from 1623.