A historical atlas is an atlas that includes historical maps and charts depicting the evolving geopolitical landscape. They are helpful in understanding historical context, the scope and scale of historical events and historical subjects (such as the expansion of the Roman Empire), and macro-history. Some historical atlases try to present the entire history of the world, such as the Historical Atlas of the World, while others are more specialised, for only one time period or location, such as the Historical Atlas of the American West or The Historical Atlas of China. They may also include historical photographs and explanatory text or essays.
The first known historical atlas was the Parergon by Abraham Ortelius in 1579, which was a supplement to the Theatrum Orbis Terrarum. William R. Shepherd produced a well-known Historical Atlas in 1911 [1].
Psychiatrist Colin McEvedy was one of the first to produce historical atlases using the same base map throughout many time periods, in his Penguin atlas of history series, which has become common in modern atlases. Recently, historical atlases have been made available online.