43. Fondaco dei Turchi

In 1438, Emperor John VIII Paleologus, the penultimate ruler of Byzantium, was desperate.

Beset on all sides, his empire had been chipped away until it was little more than the great city of Constantinople itself, the last Christian stronghold in the east. He HAD to persuade the more powerful Holy Roman Empire in the west to help him defend eastern Christianity from being overrun by the forces of Islam.

The trouble was, his eastern Orthodox church and the western Catholic church had split in a bitter schism several centuries earlier, and Rome was not very interested in offering tangible help to Byzantium unless a lot of religious kow-towing went on first.

Venice was a long term trading partner and the closest thing to a friend that Byzantium had in the west, and it was to here that Emperor John came in 1438 to try – with Venice's help - to broker a rescue deal with Rome, or anyone else he could find in Europe with an army not currently busy elsewhere.

He arrived with an entourage of 600 priests – yes, six hundred Orthodox clergy – ready to compromise with Catholic demands. He stayed six months, conceding almost everything that was demanded of him and his clerics, and went home again with no binding promises of help.

This is the building in which John VIII and his retinue stayed while in Venice. It doesn't look that old, but that is because in the mid-19th Century this huge and ancient palazzo was so dilapidated that it underwent a massive renovation, conducted according to the historian John Julius Norwich with "marvelous insensitivity".

To me, what's more important is that underneath the cleaned up surface and the new ugly Grand Canal façade, the fabric of this building is still standing. That makes this – as far as I can tell – the ONLY surviving building in the world in which one of the Emperors of Byzantium ever lived. Can you imagine what a thrill it is to stand inside it? To visualize the heated theological arguments that must have gone on in every corner of it; to empathize with the daily frustration of John, trying unsuccessfully to win support for his cause; to imagine the impatience of the Doge and his Council at having to house and feed so many hangers-on, month after fruitless month?

Ironically, once Sultan Mehmet II had destroyed Byzantium in 1453, Venice sucked up to the Ottoman Empire instead and eventually turned this very building into a trading centre and warehouse for Turkish traders, complete with mosque, which is why it is now known as the Fondaco dei Turchi.

Today, it houses the Museum of Natural History. With all due respect to the scientists whose passion that is, who the hell goes to Venice to learn about the evolution of algae in the Adriatic? What a waste of such an historically significant building! What a perfect place for a museum that could explore the amazing 1100 years that was the Byzantine era, in which Venice, more than anywhere else in the west, played such an integral part.