The Golden Horn, called Haliç or Altin Boynuz in Turkish, is a natural harbour which divides Istanbul. The Greek legend tells us that Keroessa, mother of Byzas the Megarian, gave the harbour its name. This was the place where the navy headquarters of the Byzantine Empire were, and in order to protect Constantinopolis, high walls were erected all along the shore. To prevent the entrance of unwelcome vessels, a long chain was stretched over the bay, from Constantinopolis to the old Galata Tower in the north. During the Fourth Crusade (1204), the old tower was destroyed, but the Genoese colonists built a new Galata Tower in 1348. They called it Christea Turris, or The Tower of Christ. The chain stretched across the Golden Horn was broken, or avoided, three times throughout history, as follows:

The Kievan Rus' dragged their ships around Galata and launched them again when they arrived to the Horn (in the 10th century). They were beaten by volleys of Greek fire.
During the Fourth Crusade, ships from Venice broke the chain with a ram.
The Ottoman Sultan Mehmed II, seeing that brute force wasn't enough to break the chain, used the Rus' tactic by pulling his ships across Galata with the help of wooden logs coated with grease.

The Golden Horn also appears in many classical literature works as well, such as the poem "Lepanto" by G. K. Chesterton, which says:
"From evening isles fantastical rings faint the Spanish Gun,
And the Lord upon the Golden Horn is laughing in the sun".

When Mehmed the Conqueror captured Constantinopolis in 1453, the Phanar (Fener) and Balat districts along the Golden Horn became populated by Italian merchants, Greeks, Jews and all other sorts of non-Muslim citizens. The Golden Horn is now populated on both of its edges. In 1502, Leonardo Da Vinci made a drawing of a 240m long bridge over the Golden Horn, as an engineering project commissioned by the Sultan Bayezid II.

The Golden Horn today

Istanbul's Chamber of Commerce is also on the shore here, as well as cemeteries for all major religious denominations. The Galata Bridge brings together Eminönü and Galata, and further up the Horn, there are also the Haliç Bridge and the Atatürk Bridge. The Golden Horn used to be heavily contaminated with all kinds of industrial waste, but today it's a frequented tourist location due to its beauty and rich history. Efforts have been made to clean it up and purify the soil and water. May 17th, 2006, was the day when Turkey's Prime Minister, Recep Tayyip Erdogan, as well as Istanbul's mayor, Kadir Topbaş, announced they would revive the Leonardo Da Vinci's Bridge Project. Planning has started in 1999, and now, after five hundred years, the bridge designed by the great genius of Leonardo Da Vinci, will at last come to reality in its originally intended dimensions and location. The architect in charge is Bülent Güngör, who restored the Palaces of Çiragan and Yildiz, as well as the Sümela Monastery. The Bridge itself is intended to be exactly as Leonardo Da Vinci imagined it to be in his sketchbooks, 240m long, 8m wide and 24m above the Golden Horn. On July 29th, 2006, the 4th round of the Red Bull Air Race World Series took place at the Golden Horn.