But, the sentence says “what is now Venice”. It’s Venice now, ant it was Venice then. It’s been Venice for the past 1000 years. I guess that it wasn’t “Venice, Italy”, but “Venice, The Venetian Republic” then, but I ascribe this oddity to there being “Paris, Texas” for the USA audience while the rest of the world knows that when you say Paris, you mean the capital of France and not “Paris, the nail salon down the road”. Likewise, 500 years ago, it wasn’t “Venice, the Venetian Republic” since anyone who would understand what Venice or The Venetian Republic is, would not need any qualifying of Venezia, or whatever local name they used for that city.
Anyway, the OP referred to the weirdest place in the sentence for that qualification because nothing else was qualified (was Alaska even Alaska back then? ;)