To approach Constantinople was to be dazzled by the most awesome cityscape in the world. So rapidly had it grown that the proud and ancient city of Chalcedon, on the Asian side of the Bosphorus, now served merely as its gateway. The Persian ambassadors – boarding a ship in Chaldecon’s harbour and negotiating the waters that surrounded Constantinople ‘like a garland’ – would have found marks of urban sprawl wherever they looked: for the conurbation, spreading in a ribbon along the European coastline, had long since broken through even the outermost ring of walls. Inevitably, though, it was to what lay within those hulking fortifications that the visitor’s gaze was drawn: for it was there that human effort and ingenuity had most astoundingly enhanced the already stunning setting. Along the waterfront, once a bleak wilderness of mud and reeds, everything now proclaimed the voracious appetites of the capital: a three-and-a-half mile stretch of harbours and warehouses, granaries and wharfs. Beyond them, packed so tightly together that visitors would often find themselves 'cramped and walking in danger because of the great number of men and animals’, there spread the homes of the city’s almost half a million inhabitants: a concentration of people vaster even than Ctesiphon. Nevertheless, as the Persian ambassadors neared their destination, the skyline of Constantinople would have conveyed to them an impression, not of seething clamour, but rather of order, monumentality and space. Along the spine of the promontory, the smog bred of countless furnaces and hearths, and which hung in a pall over the lower reaches of the great conurbation, diminished upon the sea breezes, to reveal the hills that originally, before the arrival of Constantine upon them, had constituted the upper reaches of Byzantium, and now provided the New Rome, and the Roman Empire itself, with its mighty heart.
The ambassadors, once they had disembarked and made their way up from the Golden Horn, would have approached these hills along a broad, sumptuously porticoed road: the Mese – 'Middle Street’. Ahead, framed by colossal arches and gateways, stretched a succession of marmoreal open spaces. It was in the first of these, at the foot of a column pointedly adorned with depictions of Roman military triumphs, that the ambassadors would have been officially welcomed to the city; it was in the second, the circular forum built by Constantine, that the Palladium, supposedly lay buried. It was not this forum, however, but a third, the square known as the Augustaion, that most magnificently embodied the capital’s pretensions. On its eastern flank stood the Senate House; to the south, adorning a massive bath-house, was the city’s foremost collection of domed and double-arched mass of brick and marble named the Golden Milestone. This was the monument from which imperial cartographers measured the distance to every known location: for just as the sun, and the moon, and the stars revolved around the earth, so too, it pleased the Romans to imagine, did all kingdoms revolve around Constantinople. She stood, in their confident opinion, upon the axis of the world. She was, quite simply, the 'Queen of Cities’.
— Tom Holland, In The Shadow Of The Sword: The Battle for Global Empire and the End of the Ancient World.