Ston (pronounced [stɔ̂n]) is a settlement and a municipality in the Dubrovnik-Neretva County of Croatia, located at the south of isthmus of the Pelješac peninsula.

Located at the gates of the peninsula, surrounded by three seas, protected by four hills, rich in fresh water and saltwater, fertile plains, it has been an important political, cultural and ecclesiastical centre.

In 533, at Salona, a diocese of Sarsenterum was established for the Zachlumia (Hum) area, which belonged to the church in Ston (Pardui).

As the secular and ecclesial powers grew, it is assumed that after the disappearance of Sarsenterum, Ston became a local ecclesiastical center.

The diocese of Ston is first mentioned in 877, as an institution from an earlier time, and the bishop is listed as a suffragan of the metropolis of Split.

At the end of the 10th century, Samuilo was the Lord of Zachlumia, and the dukedom belonged to the Doclean King Jovan Vladimir.

From 1304, Zachlumia was ruled by Mladen II Šubić, then again for a short period by a Serbian župan, and then became part of the medieval Bosnian state, acquired by Stjepan Kotromanić in 1325.

The Dubrovnik people immediately began to build and establish a new Ston, to defend the Pelješac and protect the slaves from which they had earned big revenue.

The cathedral of St. Blaise was built in 1342 by decision of the Senate after Ston joined the Republic of Ragusa, on the site of the present damaged parish church.

The restoration of the stone monuments and the reconstruction of the fortifications and the tower resumed only after 1945, however they were again damaged in the Croatian War of Independence (1991-1995), followed by the devastating earthquake of 1996.

Recently, thanks to the Society of Friends of the Dubrovnik Walls, the stone forts and towers are being reconstructed, so that the monumental stonewall complex now begins to live again in its old dignity.

First, in thirty years, one of the longest defense walls in Europe was erected on one side of the peninsula, and according to a unique project, two new towns were planned: southern Ston and northern Little Ston with the aim of encompassing people to preserve the boundaries and work in solanas the state had acquired.

The walls were of great importance because they were defending the saltworks that gave 15,900 ducats every year to the Dubrovnik Republic, the shellfish farm and the city itself.