Passage: Constantinople had been an imperial capital since its consecration as the first Christian capital in 330 under the first Christian Roman emperor, Constantine the Great. In the following eleven centuries, the city had been besieged many times but was captured only once: during the Fourth Crusade in 1204. The crusaders established an unstable Latin state in and around Constantinople while the remaining empire splintered into a number of Byzantine successor states, notably Nicaea, Epirus and Trebizond. They fought as allies against the Latin establishments, but also fought among themselves for the Byzantine throne.

Question: When was the only time Constantinople captured?
1204