1: https://gentlemanscodes.com/chivalry/the-sack-of-constantino... 2: https://en.m.wikipedia.org/wiki/Sack_of_Constantinople
Any given random person from a long time ago tends to have either no living descendants now or a whole lot of them. The sacking of Constantinople was long enough ago that probably most now people in Europe are descended from people who were involved.
When I took on of the boats around Venice I had a European couple going on about it. They kept calling it a city of thieves, shrug.
More that for a city where important pieces of the historical artifacts and art was stolen by betrayal it’s a bit ironic to complain about modern wealthy people.
As in “how dare rich opportunistic Bezos rent this city where he can see beautiful Byzantine treasures stolen by rich opportunistic Doge Enrico Don-solo.”
Then again maybe it is an intentional backdrop for the story.
As for Constantinople, historians argue about who betrayed who. The counter argument is that the Byzantines refused them promised supplies leaving them no option but to take them by force or starve.
Even the same historian in different books can make it look quite different (Peter Frankopan's description the The Silk Roads reads quite differently from one of his other books).