By the time of its formation it included the clubs from the districts of Skopje, Bregalnica, Bitola, Kosovo and Vranje.
In the early Antiquity, this area, which is geographically connected to the course of Bregalnica River or antic Astibos, was part of Paeonia, colonized by the Paeonian tribe known as the Derrones.
Articles 4 and 5 stated each country's territorial claims on Bulgarian-controlled territory (the line Gevgelija-Vardar River-Bregalnica-Osogovska Planina for the Serbs and Beles-Eleftheres Gulf for the Greeks), committed them to seek international mediation, and to meet Bulgarian armed aggression towards either signatory with all available forces.
The founders of the Slavic education, brothers Kiril and Metodij (Cyril and Methodius), stayed in the valley from the year 845 to 855 and in the Bregalnica area (Morodvis) started to preach Christianity in Slavic language.