Geography is an encyclopedia of geographical knowledge, consisting of 17 'books', written in Greek by Strabo, an educated citizen of the Roman Empire of Greek descent. In his 17 books, divided into three volumes, Strabo deals with ancient physical geography and chorography, by which he means political geography. The two are combined in this work, which makes a "circuit of the earth" detailing the physical and political features. Strabo's Geography contains a considerable amount of historical data, as he worked on his Geography and now missing History (his other work) at the same time.