When was the civilization of ancient Greece at its peak?

It reached a peak during the 5th Century BCE, especially in western Asia Minor and the Islands which led the way, and to a lesser degree at Athens when it could afford it before it lost its empire atthe end of that century.

There was a secondary surge in the 2nd and 1st Centuries BCE under the patronage of the Macedonian kings of the Hellenistic Kingdoms which were formed out of the empire of Alexander after his death, when even the hellenised Jewish aristocracy had their foreskins surgically restored so they could appear Greek when naked at the public baths.