[2] The earliest undercurrents of Mesopotamian religious thought are believed to have developed in Mesopotamia in the 6th millennium BC, coinciding with when the region began to be permanently settled with urban centres.
[1] The earliest evidence of Mesopotamian religion dates to the mid-4th millennium BC, coincides with the invention of writing, and involved the worship of forces of nature as providers of sustenance.
The very earliest undercurrents of Mesopotamian religious thought are believed to have developed in the first half of the sixth millennium BC, at the time people first began to permanently settle in Mesopotamia owing to improved irrigation.
They created the first city-states such as Uruk, Ur, Lagash, Isin, Kish, Umma, Eridu, Adab, Akshak, Sippar, Nippur and Larsa, each of them ruled by an ensí.
The Sumerians remained largely dominant in this synthesised culture, however, until the rise of the Akkadian Empire under Sargon of Akkad circa 2335 BC, which united all of Mesopotamia under one ruler and conquered areas of Anatolia, Levant and Ancient Iran.
From the 21st century BC authority was considered to lie with "the city", and the polity had three main centres of power—an assembly of elders, a hereditary ruler, and an eponym.
He was not referred to with the usual Akkadian term for "king", šarrum; that was instead reserved for the city's patron deity Ashur, of whom the ruler was the high priest.
He was annually elected by lot and was responsible for the economic administration of the city, which included the power to detain people and confiscate property.
The institution of the eponym as well as the formula iššiak Assur lingered on as ceremonial vestiges of this early system throughout the history of the Assyrian monarchy.
In time, Ashur was promoted from being the local deity of Assur to the overlord of the vast Assyrian domain, which spread from the Caucasus and Armenia in the north to Egypt, Nubia and the Arabian Peninsula in the south, and from Cyprus and the eastern Mediterranean Sea in the west to central Iran in the east.
[8][9] In the third century AD, Manichaeism, which incorporated elements of Christianity, Judaism, Buddhism, Zoroastrianism, and local Mesopotamian religion, developed.
Nonetheless, modern scholars have reconstructed a roughly accurate depiction from the surviving evidence, including Sumerian and Akkadian cuneiform and the Hebrew Bible.
[13] Mesopotamian religion was polytheistic, thereby accepting the existence of many different deities, both male and female, though it was also henotheistic,[14] with certain gods being viewed as superior to others by their specific devotees.
[15] Though the full number of gods and goddesses found in Mesopotamia is not known, K. Tallqvist, in his Akkadische Götterepitheta (1938) counted around 2,400 that scholars know, most of which had Sumerian names.
[19] The historian J. Bottéro was of the opinion that the gods were not viewed mystically, but were instead seen as high-up masters who had to be obeyed and feared, as opposed to loved and adored.
[20] Nonetheless, many Mesopotamians, of all classes, often had names that were devoted to a certain deity; this practice appeared to have begun in the third millennium BCE among the Sumerians, but also was later adopted by the Akkadians, Assyrians and Babylonians as well.
"[27] Mesopotamian temples were originally built to serve as dwelling places for the god, who was thought to reside and hold court on earth for the good of the city and kingdom.
[37] The historian J. Bottéro stated that these poems display "extreme reverence, profound devotion, [and] the unarguable emotion that the supernatural evoked in the hearts of those ancient believers" but that they showed a people who were scared of their gods rather than openly celebrating them.
[42] It was believed that the gods expressed their will through "words" (amatu) and "commandments" (qibitu) which were not necessarily spoken, but were thought to manifest in the unfolding routine of events and things.
[44] "Do not return evil to the man who disputes with you, requite with kindness your evil-doer, maintain justice to your enemy... Let not your heart be induced to do evil... Give food to eat, beer to drink, the one begging for alms honor, clothe; in this a man's god takes pleasure, it is pleasing to Shamash, who will repay him with favour.
Duties seem to have been primarily of a cultic and ritual nature,[47] although some prayers express a positive psychological relationship, or a sort of conversion experience in regard to a god.
It was thought that one of the reasons the gods gave power to the king was to exercise justice and righteousness,[49] described as mēšaru and kettu, literally "straightness, rightness, firmness, truth".
A number of examples of Mesopotamian literature show how war and natural disasters were treated as punishment from the gods, and how kings were used as a tool for deliverance.
[53] Marriages were often arranged by the parents of the bride and groom; engagements were usually completed through the approval of contracts recorded on clay tablets.
[54]: 78 The worship of Inanna/Ishtar, which was prevalent in Mesopotamia could involve wild, frenzied dancing and bloody ritual celebrations of social and physical abnormality.
Stories such as the Adapa myth resignedly relate that, due to a blunder, all men must die and that true everlasting life is the sole property of the gods.
What is known about Mesopotamian religion comes from archaeological evidence uncovered in the region, particularly numerous literary sources, which are usually written in Sumerian, Akkadian (Assyro-Babylonian) or Aramaic using cuneiform script on clay tablets and which describe both mythology and cultic practices.
This has prompted one scholar to make the claim that the Mesopotamian's "entire existence was infused by their religiosity, just about everything they have passed on to us can be used as a source of knowledge about their religion.
[64] According to Panbabylonism, a school of thought founded by Hugo Winckler and held in the early 20th century among primarily German Assyriologists, there was a common cultural system extending over the ancient Near East which was overwhelmingly influenced by the Babylonians.
[66] In March 2020, archaeologists announced the discovery of a 5,000-year-old cultic area filled with more than 300 broken ceremonial ceramic cups, bowls, jars, animal bones and ritual processions dedicated to Ningirsu at the site of Girsu.