Celestial omens were collected in Mesopotamia from at least the Old Babylonian period, eclipse omens among the earliest, and the material was shaped across the later second millennium, versions travelling as far as the Hittite capital, before the series crystallised as Enuma Anu Enlil, in the region of seventy tablets, by the early first millennium BCE.
The libraries of Nineveh, gathered by Assurbanipal in the seventh century, preserve the fullest exemplars alongside commentaries and the excerpt series that organised its use. Around it worked a profession: the tupshar Enuma Anu Enlil, the scribe of the series, was the court title of the celestial diviner, and the surviving correspondence of Assyrian kings with their scholars, hundreds of letters and reports, shows the system alive, observers across the empire writing in what the moon and Venus had done, quoting the series entry that applied, and advising the king accordingly, down to the scheduling of rituals and the political handling of eclipses. The series remained canonical in Babylonian scholarship through the Persian and Seleucid periods, copied at Babylon and Uruk while a new thing grew beside it: personal horoscopy, first attested late in the fifth century BCE, which took the old celestial vocabulary and turned it from the state to the individual. Through that turn, and through Greek transmission, the omen series stands at the head of the astrological tradition, and its modern edition proceeds tablet group by tablet group across Assyriological scholarship.