Niketas Choniates
According to a story related by Niketas Choniates, in 1189 the gate was walled off by Emperor Isaac II Angelos, because according to a prophecy, it was this gate that Western Emperor Frederick Barbarossa would enter the city through. It was re-opened in 1346, but closed again before the siege of 1453 and remained closed until 1886, leading to its early Ottoman name, "Kapalı Kapı" ("Closed Gate").