Greeks have been living in what is now Turkey continuously since the middle 2nd millennium BC. Following upheavals in mainland Greece during the Bronze Age Collapse, the Aegean coast of Asia Minor was heavily settled by Ionian and Aeolian Greeks and became known as Ionia and Aeolia. During the era of Greek colonization from the 8th to the 6th century BC, numerous Greek colonies were founded on the coast of Asia Minor, both by mainland Greeks as well as settlers from colonies such as Miletus. The city of Byzantium, which would go on to become Constantinople and Istanbul, was founded by colonists from Megara in the 7th century BC.