The Uprising of Asen and Peter originated from widespread discontent among the Bulgarian peasantry and nobility under Byzantine control during the late 12th century. Asen and Peter, brothers of the local nobility, galvanized support for independence from Byzantine rule, inspired by prior uprisings and the desire for liberation. On the feast day of St. Demetrius of Thessaloniki, which holds great significance in the Orthodox Christian tradition, they rallied local warriors and peasants, uniting them under a banner of freedom against Byzantine oppression.

The rebellion commenced in the region of Veliko Tarnovo, where the brothers leveraged their local influence to gain the support of the populace who had long been marginalized by the Byzantine administration. Their initial victories against the Byzantine forces quickly garnered further assistance from disillusioned Bulgarians, who were motivated by rising nationalistic sentiments. This movement resonated with the themes of liberation and self-governance, laying down the groundwork for a significant change in the political landscape of the region.

Over the ensuing years, the uprising escalated, forming a robust military campaign that would eventually lead to the proclamation of the Second Bulgarian Empire. Asen and Peter achieved notable victories against the Byzantines, which helped to secure their leadership and elevate the status of Bulgaria within the medieval geopolitical context. Once the Empire was established, it became a powerful entity in the Balkans, which influenced trade, culture, and politics for generations to come. The legacy of the uprising reinforced the idea of national identity and autonomy for the Bulgarian people, marking a pivotal chapter in their history.