The majority of the book is devoted to the history of the Assyrians, focussed on the mythical conquests of Ninus and Semiramis, the fall of the dynasty under the effeminate Sardanapallus, and the origins of the Medes who overthrew them. This section is explicitly derived from the account of Ctesias of Cnidus (chapters 1-34).[5] The rest of the book is devoted to describing the various other peoples of Asia. He first describes India, drawing on Megasthenes (chapters 35-42),[6] then the Scythians of the Eurasian steppe, including the Amazons and the Hyperboreans) (chapters 43-47) and Arabia Felix (chapters 48-54).