July 29, 1014, the Bulgarian army suffered defeat by the troops of the Byzantine emperor Basil II. The Battle of Belasitsa, also known as the Battle of Belasitsa, the Battle of Klyuch or the Battle of Klidion, is the culmination of the duel between the Bulgarian Tsar Samuel and the Byzantine Emperor Basil II, which lasted for decades at the end of the 10th century and the beginning of the 11th century.
The battle ends with a heavy defeat of the Bulgarians. According to the testimonies of various medieval chroniclers, the number of dead was significant, and those captured were blinded by order of Basil II, later called the “Bulgarian killer”.
At the beginning of this duel, Samuil had the upper hand, but from 1001, when Byzantium shook off its internal strife and its conflict with the Arabs, the Bulgarians began to lose their supremacy and were forced to fight for their independence. To stop enemy invasions, they build a wide fortification system blocking the mountain passes and other roads to the interior of the country.
During his next campaign in the summer of 1014, Basil II was stopped in front of one of these fortifications - the fortress-dema, erected by Samuil in the Klyuch gorge between Belasitsa and Ograzhden mountains, near today's Klyuch village. The Bulgarian troops repulsed the repeated attempts of the Byzantines to capture the barrier, but on July 29 they were suddenly attacked from behind by the detachment of Nicephorus Xiphius, who managed to bypass their positions on mountain paths.
The battle ends with a heavy defeat of the Bulgarians. According to the testimonies of various medieval chroniclers, the number of dead was significant, and those captured were blinded by order of Basil II, later called the "Bulgarian killer". King Samuel escaped death in the battle itself, but died two months later - on October 6, 1014, after suffering a heart attack at the sight of his blinded warriors.