Preparation for the conquest of Istanbul
started only one year ahead. Huge canons that were necessary for the siege
were molded. In 1452, Rumeli Castle on
the European side was constructed to control the Bosphorus.
A mighty fleet of 16 galleys was formed. The number of soldiers were doubled.
The supply routes to Byzantine were taken under
control. An agreement was made with Genoese to keep Galata
impartial during the war. In April 1453, the first Ottoman
frontier forces were seen in front of Istanbul.
The siege was starting. The important points of the conquest are chronologically
listed below:
6 April 1453:
Sultan Mehmed pitched his imperial tent by
the door of St. Romanus in Topkapi. The same day the city was besieged
from the Golden Horn to the Marmara Sea
from the land.
6-7 April 1453:
First cannons fired. Some of the fortresses in Edirnekapi were destroyed.
9 April 1453:
Baltaoglu Suleyman Bey launched the first attack to enter the Golden
Horn gulf.
9-10 April 1453:
Some of the fortresses on Bosphorus were taken.
Baltaoglu Süleyman Bey seized the Marmara Islands.
11 April 1453:
The big fortresses were bombarded by cannon fires. Holes and cracks
were opened here and there. Serious destruction inflicted by ceaseless
bombardment.
12 April 1453:
The Ottoman fleet attacked the ships protecting
the Golden Horn. The victory of the Christian
ships decreased the morale of the Ottoman army.
At the order of Sultan Mehmed, the Byzantine
ships were pounded by mortar fire, and one galley was sunk.
18 April 1453, Night:
The Sultan gave his first crucial order. The attack lasted four hours
but it was scattered.
20 April 1453:
A naval skirmish took place close to Yenikapi between the Ottoman fleet and four Byzantine warships with three supply ships full of food and weapons sent by the Papacy. The Sultan came to the shore himself and ordered Baltaoglu Süleyman Pasha to sink those ships by any means possible. The Ottoman fleet could not stop enemy's ships which were bigger. With this failure the Ottoman army lost its morale and showed the signs of defeat. Ottoman soldiers started defecting from the army. Soon, the Byzantine Emperor wanted to take advantage of this situation and offered peace.
The offer, supported by famous Vizier Candarli Halil Pasha, was rejected by Sultan Mehmed. The siege and bombardment of the fortresses with cannons continued.
During this chaos and widespread feeling of defeat, a letter from the Sultan's spiritual teacher Aksemseddin promised good news about the conquest. Encouraged by this spiritual support, Fatih Sultan Mehmed, escalated the attack, and decided to add an element of surprise: the Ottoman fleet anchored in Dolmabahce would