Historical Facts About Stuff

Greece was Huge

Greece had hundreds of colonies sprinkled around the Mediterranean.

"In the first half of the first millennium BCE, Greek city-states, most of which were maritime powers, began to look beyond Greece for land and resources, and so they founded colonies across the Mediterranean. Trade contacts were usually the first steps in the colonization process and then, later, once local populations were subdued or included within the colony, cities were established. One of the most important consequences of this process, in broad terms, was that the movement of goods, people, art, and ideas in this period spread the Greek way of life far and wide to Spain, France, Italy, the Adriatic, the Black Sea, and North Africa. In total then, the Greeks established some 500 colonies which involved up to 60,000 Greek citizen colonists" - Ancient History Encyclopedia

As early as 600 BCE, Greece established a major colony in Marseilles, in southern France. Much of Italy was covered in Greek colonies, or trading posts. North Africa was popular with Greek colonists. Turkey had many Greek colonies. Many colonies were created around the Black Sea. There is even evidence of Greek colonies in Spain, although this is disputed. 

In addition to the massive number of colonies around the Hellenic World, Greece itself was much larger than it is today. Much of modern-day Romania and Bulgaria would be part of Greece if it was still so large. The land including what is now; Serbia, Croatia, Slovenia, Albania, Hungary, Bosnia, Montenegro, Macedonia, and others, were all be Greek. 

[Side note: When I say "Greece" or "Greek", I'm talking about the collection of city-states that had the same language, culture, etc. Greece as we know it didn't actually exist until 1830.]