Roughly 1,450 years — from the Mycenaean age around 1600 BC to the Roman conquest in 146 BC.
Greece did not fall all at once. The Mycenaeans collapsed around 1100 BC, the Classical period peaked around 450 BC, and Rome made mainland Greece a province in 146 BC. The last Greek-ruled kingdom, Ptolemaic Egypt, held on until 30 BC.
