The Italians (as various city-states) played a significant role in the Battle of Lepanto.
I seem to recall that Buck Section had a segment (or 2) on this event.
The pope also had ships there. Ironically, the best Turkish commander at Lepanto was an Italian renegade, known as Uluj Ali (or Occhiali, lots of variants), later the commander of the entire Turkish navy and renamed Kilic Ali. Cervantes (who was a prisoner of the Turks for a while) praises him.
Many of the rowers on the Turkish ships were Christian slaves who were liberated because of the outcome of the battle.