 From 1420 to 1797 the Republic of Venice controlled most of Dalmatia, calling it "Esclavonia" in the 15th century with the southern enclave, the Bay of Kotor, being called "Albania Veneta".Venetian was the commercial "lingua franca" in the Mediterranean at that time, and it heavily influenced Dalmatian and to a lesser degree coastal Croatian and Albanian.The southern city of Ragusa (Dubrovnik) became de facto independent in 1358 through the Treaty of Zadar when Venice relinquished its suzerainty over it to Louis I of Hungary.