A Babylonian priest of Marduk in the early 3rd century B.C., contemporary of the Egyptian Manetho, and author of the now fragmentary Babyloniaca, a history of Mesopotamia from the creation to the reign of Alexander the Great.

What little we know about Berossus (Babylonian, Bel-Usur) comes from a few biographers in whose writings his works are still preserved. Alexander Polyhistor calls him a priest of the god Bel, in the 3rd century identified with Marduk, in the high temple of Babylon. Having been educated in the Chaldean arts, he lated founded a school of astronomy on the Greek island of Kos, where he taught Greek students the secrets of Babylonian science. He is otherwise mentioned by Eusebius as a great astronomer and historian, who took care to record the history of his people for the Greeks.

His history is now only preserved in fragments, scattered chiefly through the writings of Eusebius and Josephus. The work, titled the Babyloniaca and dedicated to the Seleucid king Antiochus I, is divided into three books. The first describes Babylon, its mythology, and the account of creation, in which the god Bel (Marduk) fights monsters of the sea and creates the world from their bodies. He then orders the other gods to decapitate him, and create men from the divine blood flowing from the wound. The hero Oannes (similar to the Akkadian Ea) rises from the sea to teach men magic, writing, and the arts of civilization. The second book begins with the first 10 kings of the world and the account of the flood, and describes history until the reign of king Nabonassar (king of Assyria 747-734). The final book is a detailed political history of Mesopotamia until the death of Alexander the Great.

The work provides a remarkable attempt at preserving Babylonian culture for the Greek world. Countless passages of the remaining fragments parallel closely much older texts written in Sumerian and Akkadian: the creation and Enuma Elish and the stories of Oannes and Ea, for example. The flood story emphasizes this attempt at proving cultural continuity; all literature, said to have been written before the flood, was carefully buried in the antediluvian city of Sippar, to be excavated once the waters dried. Berossus thus provides us with a most perfect example of the persistance of the Babylonian scribal and cultural traditions at a time when the Greek peoples were assimilating the entire middle east.