Late afternoon in May 29, 1453, Sultan Mehmet, the third son of Murad, born of a slave-girl – probably Christian – in the harem, fluent in Turkish, Arabic, Greek, Latin, Persian and Hebrew, followed by his top ministers, his imams and his bodyguard of Janissaries, rides slowly towards the Great Church of St Sophia in Constantinople.

It's unlikely that Sultan Mehmet would be sparing a thought for Emperor Justinian, the last of quite a breed: a true Roman Emperor in the throne of Byzantium, a speaker of "barbarous" Greek (he was born in Macedonia) but with a Latin mind.

Much like Sultan Mehmet, Justinian was quite the geopolitician. Byzantium trade was geared towards Cathay and the Indies: silk, spices, precious stones. Yet Persia controlled all the caravan routes on the Ancient Silk Road. The sea route was also a problem; all cargo had to depart from the Persian Gulf.