Conquest of the Keramision Plain

In 680, Khan Kuber, leading an alliance of Bulgars, Slavs and Avars, launched an offensive against Byzantine territory and succeeded in capturing the Keramision Plain, a strategically important area in the southern Balkan Peninsula. Uniting the different ethnic groups under his command, he conducted swift, well-coordinated operations that enabled him to overcome Byzantine resistance and establish control over this key territory. In the Keramision Plain, Kuber and the commander Mauros organised an attempt to capture Thessaloniki, one of the Byzantine Empire's most important cities. Despite the well-planned attack, the Byzantines managed to repel it. Their defence rested on the heavily fortified city walls, a mobilised garrison and the support of the local population, which played an important role in intelligence gathering and defending the city. 

The population brought into the region by Kuber remained a lasting presence in Macedonia, creating new Bulgar and Slavic communities that had a long-term effect on the Balkans' ethnic and cultural landscape in the following centuries.