Many attempts have been made to establish with a degree of accuracy the Babylonian chronology, but all have failed from want of sufficient documents. Previous to the Assyriological discoveries the historians depended mainly, if not altogether, on the relations of Herodotus and Ctesias, and both lived a long time after the Persian conquest of Babylon; mere travellers besides, and unacquainted with the language of the country, they were often imposed upon by their dragomans or misunderstood them.