A brief history of Istanbul

Ottoman state took Istanbul May 26, 1453. The king was Fatih Sultan Mehmet, “The conqueror”.This name was given him when he took the city at the age of 21.It seems weird a person who took the city was just 21. The reason was he was the son of the previous king. One of his saying at the age of 21 is “Either I would take Istanbul or Istanbul would take Me.” it means I extremely want to take the Istanbul.
Before Ottoman state took the city, Byzantine state had the city for 1123 years. The city was the center of the trade between Europe and Asia. For that reason the city was so important for them. The fort of the city was protecting very well with enormous, strong walls from attacks. It had well-known for the fort. Besides, there was sea around the city. In case of emergency, Byzantines were ready to stretch a chain to a strategic two points for preventing enemy ships from attacks. In history many states wanted to take the city as well as Muslim states because of the geopolitical reasons.
Why I am giving this information? One of the reasons is the Ottomans invented a new kind cannon named “sahi”, which was powerful and long range than other cannons for that time. During that period, people were living in small groups in small forts. They protected themselves in those forts easily until Ottomans used “sahi” cannons. After Ottomans used those cannons other countries transported these kind cannons. The result was those small forts destroyed from attacks. For that reason, bigger cities established. It had a big effect in history as far as I read from Turkish history books. The second reason was the king Fatih transported the ships in front of the city on land. The chain was useless. Byzantines were not expecting this. Because, it happened first time in the history. Another reason was the city was the door of the Europe. Ottomans knew that if they took the city, they would have taken many European cities easier than Istanbul. After 53 days siege Ottomans took the city.