The state of affairs about 750 B.C.
This is a follow-up post to my earlier suggestion for a game set during the time of the Cimmerian invasions. While in the east the Assyrians and Lydians are fending off the rampaging barbarian hordes, in the west the Phoenicians are extending their sway. This map shows the disposition at the time. The Phoenician colony of Carthage is the dominant city-state in the region. They are so sure of their power that they tend to regard the whole Mediterranean as their own private property, and have been known to seize ships and cargoes. Yet when the Greeks or Etruscans return the favor they're branded "pirates." A loose federation of Etruscan city-states dominates the Italian peninsula. Rome at this time was still ruled by the legendary kings. It was little more than a colony of Alba Longa, only just beginning to assert its independence. The Greeks, both Ionian and Dorian, have a strong presence in the toe and heel of Italy and eastern Sicily. They present a serious challenge to the Phoenician dominance of trade.
Although the Phoenicians counted biremes as part of their navy, and triremes were starting to appear, the most common ship plying the seas was still the pentekonter. Even a century later, at the Battle of Alalia, the Greek fleet would consist entirely of pentekonters, and decades later Polycrates, the tyrant of Samos, would wreak havoc on the Aegean with a navy of 100 pentekonters.
In addition to the usual opportunities for adventure -- treasure rich, monster haunted ruins, etc. --- the prevalence of colonies in this region presents an opportunity for an interesting variation on the standard "D&D endgame." Instead of just getting a stronghold, players reaching a certain level (either literally or figuratively if playing a game like RuneQuest) could set out to found their own city. This could become a campaign in itself, with the party playing out a scenario similar to the one in the later books of The Aeneid.