War of the Straits and Sardinian–Aragonese war: The Battle of Alghero results in a crushing victory of the allied Aragonese and Venetian fleet over the Genoese fleet, most of which is captured.

The War of the Straits or Third Genoese–Venetian War was a conflict fought between the Republic of Venice and the Republic of Genoa, and their allies, in 1350–1355. The third in a series of conflicts between the two major Italian maritime republics, the war resulted from the intense commercial and political rivalry over access to the Aegean Sea and the Black Sea. The main immediate events that precipitated the war were the conflicts over Caffa and Tanais in the northern Black Sea, control of passage through the Bosporus straits—whence the conflict received its name—and the seizure of Chios and Phocaea by the Genoese.

The Sardinian–Aragonese war was a late medieval conflict lasting from 1353 to 1420. The fight was over supremacy of the land and took place between the Judicate of Arborea, allied with the Sardinian branch of the Doria family and Genoa, and the Kingdom of Sardinia, the latter of which had been part of the Crown of Aragon since 1324.

The Battle of Alghero or Porto Conte was fought on 27 August 1353 at the Bay of Porto Conte, just off the town of Alghero in northwestern Sardinia, between the fleet of the Republic of Genoa and the allied fleet of the Crown of Aragon and the Republic of Venice. The battle was part of the War of the Straits between Genoa and Venice, as well as the Sardinian–Aragonese war, in which Genoa backed Sardinian rebels against Aragonese rule.

August 27 is the 239th day of the year in the Gregorian calendar; 126 days remain until the end of the year.