The largest Western Community?
In Ferdinand Tonnies' late 19th century classic, the book that launched sociology, he described the destruction of community and the emergence of society. It was a trend that continued, and that was accelerated by things like automobiles, apartment blocks, shopping malls and zoning.
Venice seems to have missed all this destruction. It isn't the same city it was 200 years ago, of course: it had revolutions too. But the sense of community among Venetians is much stronger than you'll find in any modern city.
So, is this the largest community in the Western world? It certainly feels that way. Despite all the guests.