It is believed that this city was already established by the 4th century before Christ and that it was under strong influence of the Greek colonies, but, only with the coming of the Romans in the 1st century did the city develop and expand. It became an important port, a political, military and trade centre. Temples, thermal spas, a forum, amphitheatre, squares, storage houses, public and residential buildings were constructed. In the battle between the Cesar and Pompeii, the town took Cesar's side, who eventually won the war. As a sign of his gratitude, he promoted it to a colony – “Colonia Martia Julia Salona”.

Salona was an important centre, which draws many to come here and find their place under the sun. One of them was Gaj Aurelie Valerie Diocletian, the Roman emperor himself. He is said to have originated from a Patrician family from this region. Before the end of his life, he wished for a palace to be built for him and decided to do it on the peninsula next to Salona, in a natural cove that faces south. It has also been stated that the Cesar had arthritis, and as there were sulphurous springs there, beneficial to his emperor’s bones, the order came: “Build me a palace!”. That is how history of Split begun.

The town of Solin played an important role in Croatia’s history as the crowning town of Croatian rulers. Its importance is also demonstrated by the numerous monuments from that era, such as the Šuplja crkva (Hollow church), ruins of a castle, treasuries and the findings on the Gospin otok (The Island of Our Lady), where diggings near the present day Solin Parish Church revealed the foundations of churches from the 10^th century, along with the grave of Queen Jelena.