It was fought in the Dinaric Alps of Eastern Bosnia near the rivers Bosna and Drina, the border area between the Kingdom of Croatia and the Bulgarian Empire.

To achieve his aim, Simeon overran the eastern and central Balkans several times, occupied Serbia and finally attacked Croatia.

[1][2] After the war between Trpimir I and Bulgarian Knyaz Boris I in 853, which resulted in a peace treaty,[3] the relations between Bulgaria and Croatia improved greatly.

[4] Simeon captured a large part of the Byzantine territory in Europe and was crowned as "Emperor of the Bulgarians" by Patriarch Nicholas Mystikos in 913.

In such a predicament, Simeon demanded Pope John X (914-928) to send him an imperial crown and to recognize the head of the Bulgarian church as Patriarch.

When the papal mission arrived in Preslav, Madalbertus started long negotiations with Simeon and the representatives of the Bulgarian church.

[8] After Simeon's annexation of Serbia the Bulgarian state bordered the Croatian kingdom under Tomislav, who was a Byzantine ally.

Bulgarians at the time when the battle started were in an unfavorable position and the Croatian army had made a surprise attack against them.

The Croats adjusted their military tactics, time and place of the battle to their opponents who possibly outnumbered them, which brought themselves a decisive advantage.

[9] The Croatian-Bulgarian war did not continue in a significant extent, no territorial changes followed,[2] and peace was concluded after the death of Emperor Simeon in 927.

Byzantine sources, specifically George Kedrenos,[17] say that the cause for Peter's peace treaty proposal was his fear that all his neighbors, the Hungarians, Croats, Serbs and other, could take the advantage of Simeon's death to attack Bulgaria.