The Byzantine Emperor Nikephoros I initiated a military campaign targeting the Bulgarian capital, Pliska, during a period of intense rivalry between the Byzantine Empire and the emerging power of the Bulgarians under Khan Krum. Following years of confrontation, in 811, Nikephoros sought to expand Byzantine influence and recover losses inflicted by Krum’s previous incursions into Byzantine territory. The campaign included a well-planned siege and tactical assaults designed to exploit weaknesses in Bulgarian defenses.

In a remarkable display of martial skill and planning, Nikephoros's forces effectively breached Pliska's fortifications. Not only did the Byzantines occupy the capital, but they also located and seized Khan Krum’s treasury, which contained precious valuables and resources, significantly boosting the Byzantine economy. This triumphant victory provided a temporary advantage to the Byzantines, instilling fear among Bulgarian subjects and allies alike.

The opening of Krum's treasury was particularly striking as it included not only wealth but also strategic resources that bolstered the Byzantine military. The capture of Pliska showcased the Byzantine military's capacity to project power and marked a high point in Nikephoros's reign. However, the victory was later met with repercussions, as Krum would seek revenge, leading to further conflicts. This military action would mark a turning point in Byzantine-Bulgarian relations, with repercussions extending well into the future.