Crossroads – figuratively, the word is full of promise: a meeting place, but also a place of parting; a turning point, in one’s life perhaps, or in human relationships; an opportunity for fateful decisions, or for cultural exchange. Over the centuries, where were the most important crossroads? Alexandria and Beirut, perhaps, where the Mediterranean traffic connected with the African and central Asian caravans; Petra, where – thanks to a tiny fissure in two parallel mountain ranges – the east-west trade route could meet up with that which ran from north to south; medieval Sicily or 15th-century Venice, thronged with merchants from all the known world. Or, above all, Istanbul.

First, its position. Lying – as Robert Byron somewhat over-fragrantly put it – at the thwarted kiss of two continents, halfway between two great seas but separated from the Mediterranean by the Dardanelles and from the Black Sea by the Bosphorus, it constitutes the perfect crossroads between north and south, east and west, Europe and Asia, Christianity and Islam. No wonder that Constantine the Great chose it in AD330 for the new capital of the Roman Empire; no wonder that, 1,123 years later, after its fall to the Turks, the conquering Sultan Mehmet II adopted it – after a simple change of name – as that of the Ottoman.