For ten points, name this city, the capital of the Byzantine Empire, which was renamed to Istanbul in 1930.
Giovanni Giustiniani died from wounds he received while defending this city. This city used a giant chain connected to the Old Galata Tower to prevent ships from accessing the Golden (*) Horn. Orban designed the giant "Basilica" cannon to target this city's Theodosian Walls in a 1453 siege led by Mehmed II. For ten points, name this city, the capital of the Byzantine Empire, which was renamed to Istanbul in 1930.
Giovanni Giustiniani died from wounds he received while defending this city.
Constantinople (do not accept Istanbul or Byzantium)