In order to easier read through the different eras of Greek history we have split Greece's history into 4 distinct periods:
Ancient Greece, which starts with prehistoric Greece (roughly late 3rd millenium BC) and lasts until the Roman rule (4th century AD)
The Byzantine period, which starts with the division of the Roman empire into East and West and lasts for roughly 1,000 years until the fall of Constantinople to the Ottomans in 1453.
The Ottoman occupation, which starts with the fall of Constantinople in 1453 and lasts for roughly 400 years, until the Greek war of independence which led to the creation of the modern Greek state (1832).
Modern Greece, which covers the period from 1834 until today.