Italy itself is a rather recent concept, surprisingly. The modern country of Italy didn't form until 1866, after a rather long series of civil wars.
Venice was it's own Republic until 1798, when it fell to Napoleon.
That makes the country of Italy rather recent (just like most European countries), not the concept of Italy. The concept of Italy is much older than the country (for example, “Italian” was used as a language in the Venetian republic, and by that it was meant Florentine)
And by venice itself we forget to mention all the coast in jugoslavia