Bulgarian Forces Destroy Byzantine Army at Pliska
Emperor Nikephoros I invaded Bulgaria in 811 and captured the capital at Pliska after rejecting peace proposals from Khan Krum. As the Byzantine army withdrew through the Balkan mountain passes, Bulgarian forces blocked its route with wooden defenses and gathered fighters from across the region. Before dawn on July 26, Krum's army attacked the trapped imperial camp. Nikephoros and many senior officers were killed, while much of the Byzantine force was destroyed trying to escape. His son Staurakios survived with a severe wound but could not establish a durable succession after returning to Constantinople.
Why it matters: Nikephoros was the first reigning Roman emperor killed in battle against a foreign enemy since Valens in 378. The victory preserved Bulgarian independence, enhanced Krum's authority, and shifted the balance in the prolonged Byzantine-Bulgarian struggle over the Balkans. It also destabilized the imperial succession at Constantinople during a period of external pressure.