The Fall of Constantinople, 1453: From the Bosphorus to Hagia Sophia

Mehmed II started planning his attack the moment he took the throne in 1451. His first move was stone: a fortress on the European shore at the narrowest point of the Bosphorus, only 660 metres across, facing an older Ottoman fort on the Asian side. Work began on 15 April 1452. Its job was to stop any sea aid, above all from the Genoese colonies on the Black Sea, from reaching the city. Each of its three main towers was named after the vizier who supervised its building.

Constantine XI ordered a defensive chain placed at the mouth of the Golden Horn harbour, floating on logs. In 1204 the Fourth Crusade had broken in from this side. The chain was strong enough to keep every Turkish ship out, and the Ottoman fleet could not force it. On 20 April a small flotilla of four Christian ships still fought its way in after heavy fighting, which lifted the defenders' morale.

Location precision: The chain's exact line is not fixed here; the pin marks the Golden Horn.

If ships cannot pass the chain, take them around it. Mehmed ordered a road of greased logs built across Galata, on the north side of the Golden Horn, and dragged his ships over the hill into the water on 22 April, bypassing the barrier. The Byzantines were demoralized. On the night of 28 April they tried to burn the Ottoman ships with fire ships, but the attempt failed with many casualties.

Location precision: Sources give the route only as across Galata; the pin marks the district.

The land walls had a gate named for a nearby church, St. Romanus. Turks call it Topkapı, the Cannon Gate, after the huge cannon, the Basilic, set up opposite it in 1453. Mehmed's guns fired for weeks, but they were imprecise and slow, and the defenders repaired most damage after each shot. On the last night the Genoese commander Giustiniani was badly wounded, and his removal from the ramparts caused panic. By tradition, Constantine XI died here on 29 May.

Location precision: The pin marks the Topkapı area where the gate lies; exact placement of the fighting is not recorded.

The Blachernae stretch juts north from the line of the land walls; built in the 11th century, it was much weaker than the rest. Shortly after midnight on Tuesday 29 May the final offensive began, and waves of irregulars and Anatolian Turkmen fighters concentrated here. The Turkmen managed to breach it and enter the city, but the defenders pushed them back quickly. Then came the Janissaries.

Location precision: Blachernae is a district at the northern corner of the walls; the breach spot is not pinned down.

On the evening of 28 May the Emperor, with Latin and Greek clergy and nobles together, attended a last solemn Vespers here. The next day, civilians crowded inside and barred the bronze gates, hoping for divine protection; the troops breached them. Mehmed entered and had the church converted to a mosque at once. He attended the first Friday prayer there on 1 June 1453, and Hagia Sophia became the first imperial mosque of Istanbul.