After the success of the Bulgarians in the Battle of the Gates of Trajan in 986, Byzantium descended into a civil war, further exacerbated by the conflict with the Fatimids in Syria. Tsar Samuil took advantage of the situation. He managed to seize many castles in the surroundings of Byzantium's second largest city, Thessalonica. In 991, the Byzantines managed to capture Roman of Bulgaria but this did not stop Samuil who was now de facto the only emperor of Bulgaria. In 996, Samuil defeated the forces of the strategos of Thessalonica and marched south, eventually threatening Larissa and Corinth.
The battle
On his way back he met a Byzantine army on the opposite side of the Spercheios river, led by the Domestic of the West, Nikephoros Ouranos. Basil II had appointed Ouranos commander of all Balkan and Greek territories of the Byzantine Empire and gave him a large army to defeat the Bulgarians. He followed the Bulgarian army and confronted it after the Bulgarians went through the Thermopylaepass onthe river of Spercheios. After heavy rainfalls, the river had swollen and flooded a large area on both shores. The Bulgarians camped on the southern shore and the Byzantines on the northern, separated from each other by the river. The two armies remained thus encamped for several days. Samuil was confident that the Byzantines could not cross, and neglected taking measures to protect his camp. Ouranos however, sought and found a ford, led his army across during the night, and attacked the Bulgarians at dawn. The Bulgarians were not able to put up effective resistance, and the larger part of their army was destroyed and captured. Samuil himself was wounded and he and his son Gavril Radomir evaded capture by feigning death among the bodies of their slain soldiers, while around 12,000 of their men were said to be captured. After nightfall they set off to Bulgaria and in the Pindus mountains gathered what was left of their army. Over the difficult 400 km journey to Ochrid, his arm healed at an angle of 140°. According to Yahya of Antioch, Nikephoros Ouranos returned to Constantinople with one thousand heads of Bulgarian soldiers and twelve thousand captives.
Aftermath
The battle was a major defeat of the Bulgarian army. At first Samuil showed readiness for negotiations but upon the news of the death of Bulgaria's official ruler Roman in prison, he proclaimed himself the sole legitimate tsar and continued the war. Although Samuil initially managed to recover, the Byzantines decisively took the lead in the war. In 1014, they decisively defeated the Bulgarians and conquered the country. According to Skylitzes, the victory was entirely Ouranos's achievement, and Basil II is credited with little besides appointing him to the office of Domesticos.
