In ancient times, the series of waterways now known as the Turkish Straits, comprising the Dardanelles (or Hellespont), Sea of Marmara and the Bosporus, formed both a divide and a bridge between Europe and Asia. Its western and eastern entrances were guarded, at different times, by two of the most fabled cities of all time: respectively Troy (in Asia) and Byzantion (or Byzantium, on the European coast). The narrow crossing points at the Hellespont and Bosporus were strategically important invasion routes while the waters themselves were vital routes of travel and commerce, particularly the supply of grain from the hinterland of the Black Sea to the Greek cities. This made them sought after prizes and sources of friction between successive empires, Persians, Macedonians and Romans among them, and ensured they were associated with some of the great names of history, from Odysseus to Xerxes, Alexander to Constantine the Great. John D Grainger relates the fascinating history of this pivotal region from the Trojan War to Byzantion’s refounding as the new capital of the Roman Empire. Renamed Constantinople it dominated the straits for a thousand years.

Professor Jennifer Tobin discusses the history of Turkey, from the time of the Trojan War through Alexander the Great.

The great city of Byzantion/Constantinople/Istanbul stands on a commanding cape overlooking a busy waterway. It has been the target of repeated attempts to capture it for the past two and a half millennia. Most of these attacks failed, but some did so in spectacular fashion, such as the great Arab sieges. The inhabitants fought hard in almost every siege, with the result that when the city was captured it was also destroyed, or at least suffered a hideous sack. Almost every nation between the Atlantic and the Steppes of Asia have made attempts to capture the city, some repeatedly but only a few - a Roman emperor, the Crusaders, the Turks - have succeeded. And there is no sign that some have given up the hope of taking it - the last sieges were just before and then during the Great War, by the Bulgars, and then by the Allies, who got no closer than Gallipoli, but the city had to submit to enemy occupation when the empire it ruled collapsed. It is still surrounded by envious neighbours, who wish to control it. The city has been besieged forty times, and has been captured on three or four occasions; it cannot be said to be safe yet. It is still 'The City of the World's Desire'.