The scholars who fled west and lit the Renaissance 

The tidy version of this chapter says that in 1453 refugees carried Greek learning to Italy and the Renaissance began. It is a good story with the causation reversed, and the true version is more interesting because it is about a slow current rather than a single flood.

Greek teaching had been arriving in Italy for three generations. Manuel Chrysoloras, usually known as Manuel Chrysoloras of Constantinople, was lecturing on Greek in Florence from 1397, and his students went on to translate Plato and to train the next cohort of Italian humanists. Byzantine delegations came west for the church councils at Ferrara and Florence between 1438 and 1439, bringing the philosopher Plethon, whose lectures on Plato left a lasting mark, and Bessarion, who stayed in Italy, became a cardinal, and spent decades collecting Greek manuscripts. Bessarion's library, given to Venice, is the founding core of the Biblioteca Marciana, and he assembled most of it before the city fell.

The pattern behind all this is economic and political rather than dramatic. Byzantium had been shrinking and impoverished for two centuries, so scholars followed patronage, and patronage was in Italy, where wealthy republics and courts were paying for exactly the expertise they had. The Ottoman advance made staying more dangerous, and each stage of it pushed another wave of teachers, copyists and manuscript owners west.

What 1453 did was end the option of return, and end the institution that had been quietly preserving classical Greek texts. Constantinople had been a copying centre for a thousand years, which is why a surprising amount of ancient literature exists at all. After the fall the surviving material was dispersed, and the market for Greek scholarship in Italy became permanent rather than seasonal. Refugees such as John Argyropoulos and later Constantine Lascaris taught the language to Italians who then produced printed Greek editions, which arrived at almost exactly the right moment. The printing press was thirty years old, Aldus Manutius set up in Venice in 1494, and a text that had existed in a handful of vulnerable copies could suddenly exist in hundreds.

That is the honest chain of events. Not a moment of rescue, but a long transfer of knowledge that a catastrophe made irreversible, landing in a place with money, curiosity and a new machine for copying. It is also a reminder that cultural inheritance is fragile in a way we tend to forget, and that most of what survives did so because someone unimportant kept recopying it.

The same year that closed the eastern trade routes was also, for the merchants of Europe, the beginning of a very expensive problem.