Trebinje is the southernmost municipality and city in Bosnia and Herzegovina. Located in East Herzegovina, it is part of the Republika Srpska entity, and its population numbers 31,433. The city lies in the Trebišnjica river valley, at the foot of Leotar, some 30 km by road from Dubrovnik on the Adriatic coast.

There are several mills along the river, as well as several bridges, including three in the city of Trebinje itself, as well as a historic Ottoman Arslanagic bridge nearby. The river is heavily exploited for hydro-electric energy.

After it passes through the Popovo Polje area southwest of the city, the river - which always floods in the winter - naturally runs underground to the Adriatic, near Dubrovnik. Trebinje is known as "the city of the sun and platan trees", and it is said to be one of the most beautiful cities in Bosnia and Herzegovina. The city is economic and cultural center of the region of Eastern Herzegovina.

Bijeljina is the city and center of the municipality of the same name in the northeastern part of the Republic of Srpska. The municipality's area is 734 km² and the total population is approximately 114,663. The city is the historical center of Semberija and one of the richest cities of Bosnia and Herzegovina. As a fertile plain town, it is one of the centers for the production and trade of food. Bijeljina is recognizable by the spacious central square, whose beauty enhances the pleasant ambience of the City Park.

In May 2012, the Government of the Republic of Srpska made a decision to change the status of the municipality of Bijeljina by which Bijeljina was granted the status of the city in 1992.

In the area of ​​Bijeljina municipality, for now the oldest confirmed traces of human life originate from the young Stone Age (5000-3000 BC). Remains from the period of the Neolithic, Bronze and Iron Age and Antique period were also recorded. Locations Gradac and Agricultural Land were searched in Batković, Glavičice, Kućerina in Dvorovi, Kočinovac village, Brodić in Triješnica, and from the ancient period, a Roman villa was discovered at the location of Prekaja in Brodac, and in Velika Obarska was found a lead tile of cult purposes with a play 'Danubian horsemen'.

The most famous Old Serbian and Old Slavic site was explored on both sides of Bistrica between the villages of Batković and Ostojićevo and consisted of 4 localities between the 7th and 12th centuries. It is especially important that a large complex of workshops in the metallurgical settlement where the ancestors in the 8th century dissolved iron and produced iron tools was explored at the Čelopek locality, as clearly evidenced by the finding of the gus - graphite pot kept in the Bijeljina Museum. At this time, the settlement of Bistrica, the likely name of Bistrica, was undoubtedly the center of the parish which encompassed the entire plain before Bijeljina emerged.

The first mention of the name Bijeljina is lost in the distant past. In the "Yearbook of Pop Dukljanin" one victory of Zahumski prince Bele - Pavlimiro against Hungarians "is mentioned in the Belina plain". Today in science it is believed that the first sure significance of the settlement of Bijeljina was that of March 3, 1446, when a Dubrovnik merchant was robbed by the people of Ilica Ban.

Bijeljina is a rare city that has only changed the entire population in only the last 500 years. For the first time it was with the arrival of the Turks in 1520, and the second time with the arrival of the Austrians in 1716. According to the Zvornik Sandzak census in 1533, only 4 villages are mentioned in the abandoned Bijeljina region: Cetvrtkovište, Mirkovci (Dašnica), Grm (Galac) and Čukojevići (Modran) with 55 houses in total. In the next census of 1548, there were 17 villages with 772 houses, of which 554 were Orthodox and 218 Muslim. From this time also is the oldest building in the Bijeljina municipality, which is the spiritual center of the Serbs of this region - the Tavna Monastery, the non-Banjanic endowment.