Several natural events shape both the Red and Black Seas (OTL) to similar conditions as the Mediterranean Sea. These lakes eventually become connected by the entrepreneuring Phoenicians. This and numerous other factors prevent many of the Mediterranean states from gaining superiority over each other. This has any effects, including the enduring Phoenician civilization (although Carthage still breaks away) multiple Greek civilizations remain fiercely independent, and the Roman Empire, whose decline began the Dark Ages and whose rise destroyed the other civilizations of the sea, does not gain superiority.
(Note-Timelines for individual civilizations or historical stages are under development)
Although sometimes being multiple states, most civilizations often act cohesively. The major players are: