The Florentine-Savoy War was an armed conflict in Italy and the Aegean between the Italian states of Savoy and Florence. Several allies joined Florence in this war, mainly Naples and the Roman Empire, in order to follow independent goals.
Savoy before the war was widely seen as a rising power in northern Italy, with its victory over the Republic of Genoa and the acquisition of some of its colonies. Florence initiated the war to prevent the Savoyards from accumulating too much power and upsetting the balance in Italy, which many began to see after their success against Genoa. Naples joined in for more or less the same concerns, although they also sought to expand their own power in northern and central Italy. The Roman Empire joined in the war to align themselves with Florence and Naples, two of the larger Italian states, as well as seize some Savoyard islands in the Aegean Sea. The Swiss Confederation joined late in the war in an effort to gain Swiss populated areas.
In the war, Florentine, Neapolitan, and Swiss forces battled the Savoyards on both land and sea. Neither side was largely able to gain the advantage, although the war did strain the economy of Savoy to the limit, ultimately eliminating them as a contender for northern Italy. In the Aegean, Roman forces were able to seize the Savoyard islands with little resistance, although this was not a considerable feat. The war had considerable consequences for the Italian states, as the victorious Naples, already strengthened with the annexation of the Papal States, conquered what was left of Savoy and formed the Kingdom of Italy, a state that would dominate the Italian peninsula for the next century.