(I'm on my productive day).
During the siege of Constantinople (Istanbul), the last standing Byzantine city tried to protect the inner walls of the city from being battered by naval bombardment and any naval breach by the Ottomans. Besides, all the other walls needed repair, due to the massive bombardment from all other directions, with the famous (or rather infamous?) cannon that Mehmed the Conquerer (a.k.a Mohammad the Conquerer) used.
Therefore, it would be a wise idea to cut access into the Golden Horn. However, this could not be accomplished by the navy, since once they were taken down, getting in wouldn't be a problem for the Ottomans.
The Byzantine were aware of that. Therefore, they put an underwater chain from the walls of Constantinople to the Genoan trading post right accross the Golden Horn, Galata.
This kept the Ottomans out of the Golden Horn, until the genious of Mehmed would prevail again. He managed to build a land-bridge with greased logs in a single night, passing the Ottoman navy into the Golden Horn over this bridge.
The next morning, when the Byzantine saw the Ottoman navy in the Golden Horn, they were vastly demoralized.
- Historically, there might be errors in the information above at some parts, but the chain exists even today, and can be seen in the Naval Museum of Istanbul (I think, hmm, might be at the Topkapi palace, as well... Oh, I feel embarassed, I can't even remember where it is!)
Constantinople (note that the chain might have been more to the south of the image, but since it's an old map, it's somewhat inaccurate, making it hard to spot where it really was):
Preview:
During the siege of Constantinople (Istanbul), the last standing Byzantine city tried to protect the inner walls of the city from being battered by naval bombardment and any naval breach by the Ottomans. Besides, all the other walls needed repair, due to the massive bombardment from all other directions, with the famous (or rather infamous?) cannon that Mehmed the Conquerer (a.k.a Mohammad the Conquerer) used.
Therefore, it would be a wise idea to cut access into the Golden Horn. However, this could not be accomplished by the navy, since once they were taken down, getting in wouldn't be a problem for the Ottomans.
The Byzantine were aware of that. Therefore, they put an underwater chain from the walls of Constantinople to the Genoan trading post right accross the Golden Horn, Galata.
This kept the Ottomans out of the Golden Horn, until the genious of Mehmed would prevail again. He managed to build a land-bridge with greased logs in a single night, passing the Ottoman navy into the Golden Horn over this bridge.
The next morning, when the Byzantine saw the Ottoman navy in the Golden Horn, they were vastly demoralized.
- Historically, there might be errors in the information above at some parts, but the chain exists even today, and can be seen in the Naval Museum of Istanbul (I think, hmm, might be at the Topkapi palace, as well... Oh, I feel embarassed, I can't even remember where it is!)
Constantinople (note that the chain might have been more to the south of the image, but since it's an old map, it's somewhat inaccurate, making it hard to spot where it really was):

Preview:
