Back in the 1400s-1500s when Venice was a republic at the height of it's power, why didn't the Venetians unify Italy?
That was time before nationalism, ''Italians'' didn't really exist in that time.
I mean you had people, but some sense of unity was lacking.
And besides, Venice was oligarchic trade republic, it wasn't some democracy or something. No real interest among their elites for such endeavor.
Because the concept of Italian nationalism first appeared in 1764 when Gian Rinaldo Carli's Della Patria degli Italiani, a very famous "much-quoted article telling how a stranger entered a café in Milan and puzzled its occupants by saying that he was neither a foreigner nor a Milanese. 'Then what are you?' they asked. 'I am an Italian,' he explained."
Reference, also, the Italic League:
They never aimed to be a continental power. Venice was a small republic that became powerful by trading with the east, built a colonial empire. They started to have lands in Italy later, and they had to deal with both the italian states, France atc. and their colonies that were always rebelling in Dalmatia. Not to mention the Turks that were also a major threat to Venice. Simply, they were really too busy to even think about it.
A sense of Italy did exist, but Venice was always paranoid about its mainland holdings. It never returned the investment required to maintain it, and the Venetians were always afraid of any ambitious governor creating a dynasty that would one day rebel and threaten the city.
Not necessarily. By the 1400s-1500s there was a unified Italian language, and there's some inklings of italian unification in Machiavellis writings, although he was more against the meddlings of foreign powers.