City has a large, turbulent and proud history. The first traces of Omis dates back to ancient times. But, the most famous part of its history are the Omis pirates from the Middle Ages.
The early period - prehistoric and ancient period
History of Omis and Riviera goes back to prehistoric times. In the area of Vruja Bay and Marusici old caves were found with traces of prehistoric people. There were found artefacts such as pottery and various tools. Age of artefacts is estimated to three to two thousand years BC
Eastern Adriatic coast was first inhabited by the Illyrians tribe in the 1st millennium BC. Greeks settled
in this area in the 4th century BC. The Roman Empire finally conquered this territory in 34 BC. In this period have been found the earliest written records of the current city of Omis. The most important monuments, which are kept at the City Museum, are the stone fragments from the Roman inscriptions. The text concludes that they were carved during the reign of the Roman emperors Tiberius (14 - 37 AD) and Claudius (41-54 AD). Near to the site was found a marble portrait of the Emperor Tiberius, and a large part of the ancient altar dedicated to the Roman Emperor Augustus (27 BC - 14 AD). Testimony that it was a significant settlement in the Roman period are the Roman graves, tombstones and sarcophagi that exist on city old cemetery.
Omis name origin
City name probably has two origins. First one is from Illyric name Onaion and Oneon which means a little hill. The second one is from Greek name Nestos for river Cetina, from which name Oneum is derivated. Town is first mentioned in history under the name Oneum (Onaeum), name which dies in early 7th century.
The medieval period
Omis. The most significant monument from this period is church of St Peter from 10th century AD. In the Middle Ages, during the 12th and 13th century, the city was ruled by dukes Kacic, who were led by Omis pirates. Pirates had a fast and lightweight boats called "Sagitta" (arrows). Name for Omis in that period was Almissa (Italian origin). Pirates led attacks on the papal galleys and merchant ships from powerful Venice, Dubrovnik, Kotor and Split. Because of succesful attacks from Pirates, against town were led two Crusader wars. The first war, which ended in victory for Omis pirates, was led by Pope Honorius III in 1221 because they attacks Crusader ships who sailed to Palestine. Second Crusade, which Omis lose, was led by the Venetians in 1286 and 1287. That defeat has marked the end of dukes Kacic rule in the town. Piracy was most successful during the reign of dukes Kacica. The legacy of Pirates were fortress Mirabella and Fortica. After dukes Kačića, the most notable rulers of the town were dukes Subic.
The period of the new age
After Dalmatia was sold to Venice in 1409, city has acknowledged authority of the state, in which it remained until the 1797 (year of the fall of Venice). But Venice didn't manage to conquer the city of Omis until the 1444. And they managed it only with the help of the growing Turkish Republic. The fall of Omis has ended the rule of Pirates in this part of Adriatic sea. Despite it, town never fell in Venice hand, because of the rebel forces that had gathered outside the city walls. During the rule of the Venetians city was surrounded by walls on three sides. On the north side the city was protected by mountains. The remains of these walls are visible even today.
After Venice town fell under the rule of Austria. With short interruptions (France ruled Omis from 1805 -1813) Austria ruled the town until the end of the First World War. Only after the arrival of industry and tourism in the early 20th century Omis will resume upward path in its development.