Istanbul has always been a settlement area from early ages onwards due to its geographic location. Among centuries, it has become a centre where different cultures and religions are combined, survive and succeed.
Istanbul is famous as being one of the most besieged cities on earth. Before it was conquered by Turks, the city was attacked by Persians, Athenians, Macedonians, Arabs, Bulgarians and the armies of the fourth Crusade which headed directly to Istanbul and attacked twice.
Earliest settlements in Istanbul were observed in prehistoric periods. Continual settlements have started in the colonial period. Excavations at the tip of the Golden Horn and on the Asian side have revealed finds dating back to the 3rd millennium BC. One of the earliest settlements known in Istanbul was Semistra which dates back to 1000 BC. Semistra was followed by a small nice fishing village named Lygos and today Topkapi Palace stands over here. When Greece was invaded by Dors, Megarians run away from Greece around 680 BC and founded the city of Chalcedon on the Asian shore which is today’s Kadikoy. Some Megarians also settled down in the environment of Sarayburnu (Lygos) on the European shore opposite Chalcedon in 660 BC under the leadership of Byzas and named this place Byzantium. So the history of Byzantium started in 7th century BC by the colonists coming from the city of Megara in central Greece and from Aegean city of Miletus.