Anu

An (Sumerian An, Akkadian Anu and Anum) was the city god of Uruk and Der. In the cuneiform script, an eight-pointed star (-) is his sign, which was prefixed to all other gods' names as the determiner Dingir/Diĝir. With the exception of his ancestors Uraš, Anšar, and Kišar, he was the ancestor of all the gods of the Sumerian, Akkadian, and Babylonian pantheons. An is the Sumerian word for "heaven" or "above".

When heaven and earth separated and the universe came into being in its present form, he became the ruler of heaven. His attributes were incorporated into many other ancient Near Eastern deities. Nevertheless, An was a colorless god of whom relatively little is known and who took a back seat in lore to his more important children. When An was described, it was usually as a sullen, unfriendly, and rather misanthropic god. Anu is the patron god of exorcists, one of his epithets being mupaššir nambûrbe idāti itāti limnēti šunāte pardāte la ṭādâte, "He who gives power to exorcistisms to prevent, with the pašāru, events of bad omen and the effects of confused and godless dreams" (King BMS 62 + 1. 12).

In older Sumerian texts the earth goddess Uraš is his wife. In more recent ones it is Ki (Sumerian for earth) or his daughter Inanna. In Akkadian tradition, An was the husband of the goddess Antum, who was derived from Ki. He was also the father of Martu, Erra, Baba, Gibil, Nisaba, Enlil, Gatumdu, Lamaštu, the weather god Iškur (also known regionally as Adad, Addu, and Hadad), and the Seven Gods, among others. When Sin, Šamaš, and Ištar/Inanna tried to share world domination with An, An sent his child, the Seven Deity, against Sin, who surrounded Sin, causing a lunar eclipse. Only Ea was able to free Sin.

The cult of An receded into the background in Babylonian and Assyrian times, being overshadowed by Marduk and Assur. However, there is said to have been a renaissance of the cult of Anu-Antum in Uruk in the 3rd century BC in Seleucid times.

An played a more important role in astronomy, where the band along the celestial equator was called the ways of Anu. The fixed stars traversed three zones: either the ways of Enlil to the north, the ways of Anu in the middle zone, or the ways of Ea (Enki) south of the celestial equator. The 70 tablet canonical cuneiform tablet series Enuma Anu Enlil contains 7000 omens associated with appearances of the moon, sun, planets, and fixed stars.