How did the geography of Greece shape its earliest kingdoms, and what factors contributed to the decline of those kingdoms?

During the Bronze Age, which for Greek history is called the “Helladic period,” early settlers in Greece began establishing small communities contoured by the mountains and small plains that shaped the land. These communities sometimes joined together to form kingdoms, most prominently the Minoan kingdom on the island of Crete and the Mycenaean kingdom on the mainland. The Minoan and Mycenaean societies flourished for centuries until the Bronze Age Collapse, when Greece entered a period of decline known as the Dark Age (ca. 1100–800 B.C.E.). Epic poems composed by Homer and Hesiod after the Dark Age provide the poets’ versions of what life may have been like in these early Greek kingdoms.