Human occupation on the site of Troy (Ilion) began in the Early Bronze Age (late 4th millennium BC). The first defensive wall round the citadel was built around 3000 BC and expanded twice, attaining a diameter of c 110m at the end of Phase I, around 2500 BC.
There was steady development and regularization of the settlement plan in the following five centuries (Troy IIV) to the end of the Early Bronze Age. Around 2000 BC there was a dramatic cultural change, with reconstruction of houses and walls in stone. The town expanded considerably outside the original walled settlement, and Troy VI (from c 1700 BC) may have covered the entire plateau, making it one of the largest towns in the Aegean region. Goods imported from Mycenae and elsewhere in Greece give an indication of its important trading role.
In 188 BC it was identified by the Romans as the Ilion of Homer and recognized as the mother-city of Rome (Ilium Novum), being granted exemption from taxes. It was sacked in 85 BC during the Mithridatic War and not rebuilt until around 20 BC, following a visit by Augustus. The town prospered under Roman rule, despite being devastated by Herulian raiders in AD 267, and survived a severe earthquake in the early 6th century. Abandoned once again in the 9th century, it was reoccupied in the later Byzantine period and not finally deserted until well into the Ottoman period.