Polybius, himself a Greek and an active contemporary participant in political relations with Rome, wrote the forty books of his Universal History primarily to chronicle and account for the Roman conquest of Greece between 200 and 167 B.C. He saw that Mediterranean history, under Rome's influence, was becoming an organic whole, so he starts his work in 264 B.C. with the beginning of Rome's clash with African Carthage, the rival imperialist power, and ends with the final destruction of Carthage in 146 B.C.