Chaldean — Berosus,

It was, as might be expected, a Chaldean — Berosus, a priest of Bel Marduk at Babylon — who in about 260 BC came to the island of Cos, where there was a medical school at which Hipparchus had taught, and set up there a formal school of astrology which was perhaps the earliest such establishment. He seems to have used for his textbook a treatise called The Eye of Bel, which existed in the form of seventy tablets in the library of Assurbanipal, but was compiled much earlier, in the 3rd millenium BC, for Sargon I — or so it was said. Berosus also wrote an enormous history of his homeland, Babylonica, covering some five hundred thousand years from the creation of the world to the death of Alexander the Great, setting out in it a considerable amount of astronomical/astrological lore: about the Great Year, for instance, and the theory that earthquakes were caused by planets being in conjunction with the Sun. He also predicted a cataclysmic world disaster when all the planets were in conjunction in Cancer: the earth would become mud during an inordinate flood, and the world would eventually be covered with water, sweeping away all human life.