Constantinople was the capital of the Roman and Byzantine empires for eleven centuries — the largest, richest and most heavily fortified city in medieval Europe, and the one every power around it wanted.
Constantinople was the capital of the Roman Empire, and then of its eastern continuation, from 330 until 1453 — eleven hundred and twenty-three years, which is longer than any other city has served as the seat of a single state in European history.
It was built where it was for one reason: the site controls the Bosphorus, the only water route between the Mediterranean and the Black Sea, and sits on the land route between Europe and Asia. Whoever held it taxed both.
For most of the Middle Ages it was also simply the largest thing anyone had seen. Western visitors — crusaders, Rus' merchants, Scandinavian mercenaries — describe it in terms that read as exaggeration until you realise they are trying to describe a city of several hundred thousand people to audiences whose largest town held five thousand.
The site was already old. The Greek colony of Byzantion had stood on the promontory since the seventh century BC, and it had been taken, destroyed and rebuilt several times before Constantine I chose it.
He refounded it as his capital in 330, and the choice was strategic rather than sentimental: Rome was badly placed for an empire whose threats were on the Danube and the Euphrates, and the new city sat between them. It was called New Rome officially and Constantinople in practice almost immediately.
The Roman apparatus was reproduced deliberately — a senate, a forum, seven hills claimed on a peninsula that does not obviously have them, free grain for the citizens, and a hippodrome. What made it different was that it was Christian from the start, with no pagan temple establishment to accommodate.
The city's survival is a story about masonry. The land approach is a four-mile neck between the Sea of Marmara and the Golden Horn, and in 408–413, under the child emperor Theodosius II, that neck was closed by the most effective fortification built anywhere before gunpowder.
The system was in depth: a moat sixty feet wide, then a low outer wall with its own towers, then a terrace, then an inner wall about twelve metres high carrying ninety-six towers. An attacker who took the outer wall stood on open ground beneath the inner one.
It worked for a thousand years. Avars and Persians in 626, Arabs in 674–678 and again in 717–718, Rus' fleets, Bulgars, and the Ottomans in 1422 all failed against it. It was breached exactly once by assault, in 1453, by cannon that had not existed when it was designed — and even then the walls held for fifty-three days.
The church of the Holy Wisdom was built for Justinian I between 532 and 537, after riots had burned its predecessor, and it was finished in five years — an almost impossible schedule for a building of that size, and one that shows in the structural problems that followed.
Its dome is thirty-one metres across and rests on pendentives above an open square, which had not been done at that scale before. The first dome collapsed in an earthquake in 558 and was rebuilt steeper; the building has been repaired, buttressed and re-domed repeatedly since.
It remained the largest church in Christendom for nine hundred years, until Seville cathedral. Justinian is supposed to have said on entering it that he had outdone Solomon — a story from a much later source, and one everybody repeats because it is the right thing for him to have said. After 1453 it became a mosque, and the minarets in the photograph date from then.
A city of that size in the sixth century was an engineering problem before it was anything else, and Constantinople solved it with water. The aqueduct of Valens brought supply from Thrace along a channel more than two hundred and fifty kilometres long, and it fed open reservoirs and roofed cisterns beneath the city — the Basilica Cistern alone holds eighty thousand cubic metres.
Food came by sea. Egyptian grain fed the city until the Arab conquest took Egypt in the 640s, after which Thrace and the Black Sea had to replace it — a change that shrank the population permanently and made control of the Bosphorus a question of survival rather than revenue.
The public life of the city ran along the Mese, the colonnaded main street, from the Golden Gate through a sequence of fora to the Augustaion and the palace. Its politics ran through the Hippodrome, where the chariot-racing factions — the Blues and the Greens — functioned as something between supporters' clubs, militias and political parties, and where the Nika riots of 532 nearly ended Justinian's reign and killed tens of thousands.
The Great Palace complex on the point below the Hippodrome was the seat of government for seven centuries, and the way it worked is documented in extraordinary detail because an emperor wrote it down.
Constantine VII's Book of Ceremonies records the ritual of the court — processions, receptions, acclamations, what was worn and said and in what order — with the thoroughness of a man who had spent decades with nothing to do but observe it.
The purpose was political. Foreign envoys were received in rooms with mechanical golden birds that sang and lions that roared and a throne that rose towards the ceiling, and Liudprand of Cremona, who saw them in 949 and again in 968, records both his astonishment the first time and his irritation the second. Ceremony was the empire's cheapest weapon, and it used it constantly.