80. Annexe marks the spot

This beautiful atrium staircase belongs to the historic Hotel Danieli (see 'Palazzo Dandolo: May 31), one of the busiest and most expensive 5-star hotels in Venice. The hotel is popular with well-heeled tourists, but less well-regarded by some Venetians, for reasons that I'll come to.

In 1171, the Emperor of Byzantium arrested all 10,000 Venetians in Constantinople and seized all their assets. Doge Vitale Michiel II immediately raised a fleet of 120 warships and set sail for the Byzantine capital. On the way, he was met by ambassadors from the emperor who convinced him that a negotiated settlement was possible, so he parked his fleet at Chios, and sent his own ambassadors ahead to Constantinople.

He was conned. The Emperor had no such peaceful intentions, he was just playing for time, building his own defences, and he treated Venice's ambassadors with contempt. Unfortunately, while the wasted months went by, plague broke out in the overcrowded warships and rather than face a mutiny, the Doge led his depleted armada back to Venice, without achieving anything at all.

When he confessed the failure and humiliation of his mission to a general assembly, and when they found out that he had also brought the plague back to Venice with him, a mob formed outside the palace baying for Vitale Michiel's blood. He slipped out a side door, hoping to take refuge in the convent of San Zaccaria nearby, but the mob caught him along the quay and one of them stabbed him to death.

There is no monument to the unlucky Doge Vitale Michiel II in Venice, but until recently his death was commemorated in a different way. His assassin was tried and executed, and the killer's house – which was next to this former Palazzo – was razed to the ground, and it was decreed that no stone building should ever be erected on that spot.

The decree stood for more than 750 years, until the owners of this hotel convinced the city to repeal it so that they could extend their premises and build a modern annexe on what for centuries had effectively been vacant land. The building approval was very controversial at the time - and in fact it still is - and the hotel was very fortunate that they were allowed to put a modern hotel building in such a prominent and historically significant location, on the Riva Schiavoni so near the Doge's palace.

I doubt that the hotel makes many of its guests aware that they are sleeping where the city's most notorious assassin used to live.