Help me understand Greek mythology and historical context behind it
Title. When we say "ancient Greece" and think about it's society, it's city states (polis), it's society, it's religion, it's temples, agoras, etc... it's science, philosophies, etc... we think of Classical Greece. Period of ancient Greek history that lasted from roughly 500 B.C. to the rise of Philipe the Great, father of Alexander.
Classical Greece is actually not as old as we think. It developed from Archaic Greece, a period that lasted from roughly 800 B.C. to roughly 500 B.C. That was the period characterised by the forming of the city states and characteristic Archaic art. It was also the time of ancient poets such as Homer or Hesiod, who were pretty much the chronologers, who collected various tales and sang them or written them down.
But before the Archaic Age there was... well, nothing. The Age of Darkness, that lasted from roughtly 1180 B.C. to 800 B.C. a period lost to us that we hardly know anything about, we can only speculate.
And here we come to the possibly the most important and mysterious event in ancient history, the Great Bronze Age collapse. When all civilization that flourished in eastern Mediteranean during the Bronze Age (roughly 3000 B.C. to 1180 B.C.) collapsed in a span of few decades.. that is, all but one, Egypt. Egypt is unique Bronze Age civilization that survived the collapse and continued to flourish for several more centuries, though the collapse of their trading partners meant it lost it's economic monopolly and the Age of Iron meant that it lost it's military dominance, causing Egypt to eventually loose it's power and never regain world dominance.
During the Bronze Age, a mysterious Mycenaean civilization flourished in Greece. A civilization that was completely different to Classical Greece and that's more or less completely lost to us. We hardly know anything about it. All we have are several palatial ruins, a few artifacts and a few tablets that archeologists managed to desipher somewhat though to what degree is disputed. We don't really know how their society looked like, how their cities functioned, or even what religion or gods they worshipped. We can only guess from the tablets.
Their cities, most notable being Mycenae, were mostly fortified palaces. They didn't build Temples like Classical Greeks, but rather worshipped in home shrines or larger shrines in the open or the Palaces. They likely worshipped gods, or rather some of the gods, that would later become the Olympian pantheon. They were likely a highly monarchistic society ruled by a god king, something akin to other Bronze Age civilizations (like the Pharaoh in Egypt). They used war chariots rather than mounted warriors or strong infantry, again, something akin to other Bronze Age civilizations.
They spoke some form of Greek... or rather their language would heavily influence something that would later become Greek. Though weather they were Greeks themselves is heavily debated even to this day. The Greeks, or rather Hellenic tribes, would migrate to what is now Greece either shortly after the Bronze Age Collapse, Ionians and Aeolians (whose migration might have caused the Mycenaean civilization collapse though that's debated), or some time during the Dark Ages, Dorians. People that formed the Mycenaean civilization, scholars some times call them the Achaeans like Homer does, were thus not "entirely Greek". We don't really know who they were. We know they were not the original inhabitants of Greece, those were the Pelasgians who lived in Greece during the Stone Age. The Achaeans migrated to Greece some time during the early Bronze Age. Some theorise that they came from the Middle East, some from Central Europe, some from Western Mediteranean... we have no clue.
Here's where we come to the interesting part. The Mycenaean civilization was lost even to ancient Greeks, even during the Archaic period. Greeks from that time liked to think of that period as their glorious past that they've known nothing about. The Age of Heroes who battled various monsters and saved the world many times. All Greek heroes, Heracles, Jason, Perseus, Odysseus and the entire Trojan war... all happen during the Mycenaean Greece.
The myths take place over a century and a half, with Perseus being chronologically the first, and the Odyssey the last ending just before the Bronze Age Collapse. And clearly, in many ways they preserve the events of the past as stories. Hence why the myth of Cadmus and Europa tells of the foundation of the Minoan civilization (an even older and more mysterious civilization that might be as old as 2500 B.C. that coexisted and traded with the Mycenaeans but have collapsed around 1600 B.C, centuries before the Bronze Age collapse likely due to the eruption of a volcano in Santorini) and the myth of Theseus tells about its collapse. Similarly the Illiand and the Odyssey likely talk about nothing else than the Bronze Age collapse, with Troy symbolizing the civs of the Bronze age, and the invading Greeks the people that ultimately caused it.