A relative humidity level between 40% and 50% is generally considered to be the most comfortable. Anywhere from 30% to 60% is acceptable, but ideally you want to avoid the extremes of that range.
Ancient Greek civilization began around 1600 BC, at Mycenae and in Crete. It ended with the annexation of Greece by Rome in 146 BC. It was at its height around 431 BC, when the Peloponnesian War between Sparta and Athens began.
This includes the conquests of Alexander the Great, and ends with the conquests of the different Hellenistic states by Rome (146-31 BC). The history of Ancient Greece falls into four major divisions. The Archaic period, when the civilization's main features were evolving, lasted from the 8th to the 6th centuries BC.