Did polytheism really precedeed monotheism? And not the other way around? I mean in ancient times almost every city or tribe had its own SINGULAR patron - a deity it worshipped, e.g. Nippur had Enlil, Eridu had Enki, Athens had Athena, Thebes had Amun.
Could it be that before uniting these cities - ancient civilisations were primarly monotheistic, but really fragmented in this regard, i.e. the religious influence of each monotheistic god wasn't greater than one tribe or city. And it wasn't until later when these cities were united into nations that their deities were also united into pantheons due to greater cultural exchange and desire for greater inner stability of early states?
As far as we know, the earliest known civilizations were polytheistic. The Sumerians, e.g., believed in many gods dating as far back as 3,000 BCE. There is no evidence that worship was limited to a single deity associated with a city, although cities did have patron or namesake deities. In fact, the Sumerians, Akkadians, Assyrians, and Babylonians all worshipped basically the same set of deities despite cultural differences. Likewise, the ancient Egyptians had an incredibly large pantheon of gods. In Egypt, pharaoh Akhenaten attempted to impose a monotheistic belief in Aten, the sun disc, but this shift from the earlier polytheism to monotheism was not widely accepted by the ancient Egyptians as evidenced by the desecration of Akhenaten's images and capital city, Armana, after his 17 year reign ended. In ancient history terms, monotheism does not emerge until Judaism and Zoroastrianism in about 1000 BCE. One thing I do find interesting is the large numbers of small carved female figures found throughout much of Europe, dating back to 30,000 to 22,000 BCE, such as the Woman of Willendorf. These may represent a belief in a fertility goddess, but it is not known for certain that these figures were meant to represent a deity.