It is possible that this complex consisted of two parts in the early medieval period – the Old Fort (Stjepan grad) and Mala gradina, and that this twin settlement lasted at least until the mid-tenth century.

Turbulent political events, particularly after the tenth century, did not have any essential impact on the economic development of the town besides the occasional ramparts.

The prince of Hum, Miroslav, held court in Blagaj (Orbini, II Regno, 350) where he constructed a church dedicated to Saints Cosmas and Damian.

The first written reference to it is a peace accord between Duke Sandalj Hranić and the Venetians, from November 1, 1423, issued “in our town of Blagaj”.

[3] Unlike other fortifications that were also rulers’ residences in Bosnia and Herzegovina, the Blagaj fort is on a naturally flat site above vertical cliffs to the south, west and north.

A comparison of the walls' structure enables one to track the various stages of construction and repair - from the earliest beginnings of the fort in the fourth century.

The walls of the first stage of construction are of quarry stone laid in horizontal layers (opus incertum), similar to the palace in Mogorjelo.

In the second stage, which lasted between 535 and 600, the walls were repaired and in places built up to a height of 1 to 3 metres (3.3 to 9.8 ft), using the technique of stone laid slantwise (opus spicatum).

In the archaeological stratum dating from the Ottoman period, the only finds consisted pottery shards and small items of ironmongery used in construction.

As a result of the excavations, it was concluded that Blagaj had no remains of antique and early mediaeval architecture because there was no any archaeological material from that period.

[5][6] The historic site of the Old Fortress in Blagaj (also known as Stjepan grad) is placed under the state protection and declared National Monument of Bosnia and Herzegovina by KONS on 6 December 2003.