The Greek polytheistic religion- unknown to some- extends past simple ancient Greece.
Mycenaean Greece (from around 1750BCE to 1050BCE) is often referred to as the “mother” for the ancient Greek religion; as it is really as far as we can go back into Greek religion as we know it today without hitting a wall of rocky, unknown or opinions. However, there was also a predecesor to Mycenaean religion- appropriately refered to as the Minoan religion. This religion was an almost mono-theistic religion, with possibilities of multiple gods being more likely just “aspects” of the main goddess and God. Of course, we have hardly anything to talk about with this as we don’t really have many artefacts from that time that relate to its religion, as it was apart of the bronze age.
It is believed that they had two main gods; a female and a male. It is possible that these two gods are proto-Zeus and Hera, as the main goddesses' associations with snakes syncrotise with Hera's as well as with the Male god's apparent "reign supreme" status. However, the lack of hard evidence for this theory makes this speculation purely opinion.
Sometime from Minoan Greece and Mycenaean Greece, gods split out and became more fully-fledged and distinct- possibly from trading routes, invasions, or foreigners entering the region.
Many of the current gods we know and love today are mentioned in Mycenaean linear B texts. Gods like Ares, Dionysus, The Anemoi, Enyalius, Hephaestus, Hermes, Zeus, Poseidon, and goddesses such as Artemis, Demeter, Eileithyia, Eos, Erinyes, Hera, Leto and Athena were all names deciphered. There is a possibility that Apollon, Hyperion and Dione is included within this Pantheon- however there isn’t much more to suggest this other than the similarity in how their names were pronounced, and the fact there is a similar god who is believed to be a precursor to Apollon because he shares some similar attributes in regards to health and being an atendee of the gods- but, the same god could also be a precursor of Asklepios. As such, it is futile to try form definitive conclusions when we really only know so little.
Unsurprisingly and like many other religions and cultures, ancient Greece also has a few imported gods with the most notable being none other than the goddess Aphrodite, who was brought over alledgedly by the Phonecians when they landed on the Island of Kythera. Aphrodite is almost the exclusive god who I can confidently is non-greek in origin- by no means does this indicate she is the only one, she is simply the easiest to trace. Why? well, simply because tracing the etymology of gods and beings who can possibly be up to thousands of years of age just to find out “who” or “where” a god came from is something that requires degrees and resources I simply dont have
