The Largest Contiguous Empire

This 1930 map shows the extent of the Mongolian Empire in 1250. At this time the empire covered over nine million square miles, making it the largest contiguous empire in world history.

Image: “Mongolenreich nach 1250: Städte und Strassen.” [Mongol Empire after 1250: cities and streets.] by Otto Neurath (1930). From the David Rumsey Historical Map Collection (https://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~325155~90094112:Mongolenreich-nach-1250–St%C3%A4dte-und)