On August 20, 917 c. the Bulgarian troops, led by Tsar Simeon I, defeated the troops of Byzantium in the Battle of Acheloi. The battle was provoked by Byzantium, whose main goal was the neutralization of the growing Bulgarian state after the humiliating conditions for Byzantium reached in 913. It was then that Prince Simeon was recognized with the title “Tsar of the Bulgarians”.
Empress Zoya and the rulers of Constantinople decide once and for all to defeat King Simeon. First they make a peace treaty with the Arabs and secure their backs, then they try to build an anti-Bulgarian alliance. Kherson strategist John Vogas is sent to recruit the Pechenegs to be transferred across the Danube by the Byzantine fleet to strike behind the Bulgarians. And the strategist of Durrës, Leo Ravnukh, tried to incite the Serbian prince Petar Goinikovich against Simeon, and through him, the Magyars. The goal is to hit Bulgaria simultaneously from all sides.
Zakhilm prince Mikhail Vishnevich warned Simeon about the moves of Leo Ravnukh, and he managed not only to prevent the Roman-Hungarian alliance, but also to make his until recently northern enemy an ally. The diplomatic battle for the attraction of the Pechenegs was also won by the Bulgarian king, who far-sightedly established his first alliance with them as early as 896.
The battle left an indelible memory among the Byzantines (according to Leo the Deacon, who lived 50 years after the battle, “heaps of bones can still be seen near the river Acheloi, where the Roman army was then shamefully cut down”).
This victory also had an important psychological effect on the Byzantine army, which, seeing that it was losing the battle, fled. In a desperate attempt to stop the Bulgarians on their way to Constantinople, the Byzantines gathered the remnants of their army near the village of Katasirti and were defeated again in a night battle.
For the first time in Bulgarian history, on the initiative of Tsar Simeon I, a water-light ceremony was held for the Bulgarian battle flags before the battle at the Aheloy River.
Later, the ritual began to be performed every year on Epiphany (Jordanovden), not just before a battle. The tradition was restored in 1880 by the first Minister of War after the Liberation, Pyotr Parensov. After a break in 1946, the tradition was resumed on January 6, 1992.