War of the Straits: The Battle of the Bosporus is fought in a stormy sea into the night between the Genoese, Venetian, Aragonese, and Byzantine fleets.

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 Battle of the Bosporus or Bosphorus took place on 13 February 1352 during the War of the Straits, between the fleet of the Republic of Genoa on one side and an allied fleet of the Republic of Venice, Kingdom of Aragon, and Byzantine Empire on the other. The battle was begun late during the day and was fought largely during the night in the narrows of the Bosporus amidst a storm, resulting in a confused fight with high casualties on both sides. The Genoese were left as the victors, having suffered fewer casualties and remaining in place while the allies withdrew. The battle forced the Byzantine emperor John VI Kantakouzenos to come to terms with Genoa, exiting the war and confirming the de facto independence of the Genoese colony of Galata from the Byzantine Empire.

February 13 is the 44th day of the year in the Gregorian calendar; 321 days remain until the end of the year.