A thousand years, everyone says. Almost. Fans rebuilt them in 60 days, crusaders went round them, cannon damaged them, and the famous story of the end is probably made up.
Theodosius II's prefect Anthemius finished the first phase in 413, a law of the time says; an inscription found in 1993 gives nine years' work, so the start is argued. The new line almost doubled the city.
Three lines: a moat, a low outer wall, an inner wall about 12 m high, 96 towers.
Then, 6 November 447: an earthquake, 57 towers down, Attila threatening the Balkans. The chariot-racing factions, the football fans of their day, picked up the stones. Chroniclers and inscriptions at the walls say: 60 days.
They held. Avars and Persians, Arabs, Rus', Bulgars, even Ottoman cannon in 1422.
In 1204 the Fourth Crusade didn't beat these walls; Venetians stormed the weaker sea walls on the Golden Horn.
In 1453 the Ottoman guns worked the weakest stretch, the dip into the Lycus valley near the Gate of St Romanus. By about 7 May all three lines were breached; on 29 May the main entry came through the Topkapı breach. One account still says the artillery never got through.
The legend: a small gate, the Kerkoporta, left open, letting in about 50 Ottoman soldiers. Only Doukas tells it. Feridun Emecen calls it inaccurate, probably adapted from older legends; excavations found no matching gate.
Walk from Topkapı (the Gate of St Romanus) north to Edirnekapı, through the Lycus valley to the Mihrimah Sultan Mosque: the stretch the guns hit. Weekday morning, daylight; parkland flanks the course, but paths and closures are unverified. Crowd version: Yedikule Fortress, opening status unconfirmed when we checked.
