Basil II Crushes the Bulgarian Army at Kleidion

On July 29, 1014, Byzantine forces confronted the Bulgarian army at the pass of Kleidion along the Strumitsa River, near the modern village of Klyuch. For almost three decades, since his defeat at Trajan's Gate in 986, the Byzantine emperor Basil II had waged relentless campaigns to dismantle the Bulgarian state, which was headed by Emperor Samuel. Facing annual Byzantine raids that chipped away at his territory and prestige, Samuel decided to bar the traditional invasion routes by erecting a heavy wooden palisade, trenches, and towers between the Belasitsa and Ograzhden mountains.

When Basil arrived at the pass, his initial frontal assaults against the fortified wooden wall were turned back with heavy casualties. Samuel attempted to draw the imperial army away by sending a separate force south toward Thessalonica under the noble Nestoritsa. That diversion ended in failure when Thessalonica's military governor, Theophylact Botaneiates, crushed the Bulgarian detachment outside the city and then marched north to reinforce the emperor at the pass. Even with these additional troops, the direct route through the valley remained blocked by the Bulgarian defenders.