Croatian–Bulgarian battle of 926

The Battle of the Bosnian Highlands was fought between the huge armies of the two most powerful Balkan rulers of the time: Bulgarian Tsar Simeon I, the great victor of the Battle of Anchialus over the Byzantine Empire ten years earlier, and King Tomislav of Croatia, the first king of the growing Croatian state.

According to Theophanes Continuatus (The Continuer of Theophanes`s Chronicle) and other historians, the battle took place on May 27, 927 and was fought in the area of the highlands of Eastern Bosnia near the Drina River, the border area between the Kingdom of Croatia and Bulgarian Empire.

The Bulgarian ruler, Symeon, was a wise and able man with a restless and insatiable spirit. He spent his entire life fighting battles with neighboring countries. His basic aim was to defeat the Byzantine Empire and conquer Byzantium. To achieve his aim, Symeon overran the eastern and central Balkans several times, occupied Serbia and finally atacked Croatia.

The events developed as follows.

After long wars and great success, capturing a larger part of Byzantine territory in Europe, Symeon the Great proclaimed himself Emperor and took the title "Emperor of the Bulgarians and Greeks" at the beginning of 925. According to the juridical reasoning of the time, only the Pope and the Byzantine Emperor could bestow royal or imperial titles, and an emperor might be crowned only by a patriarch. Byzantine Emperor Romanus Lecapenus protested bitterly against Symeon`s usurpation of the imperial title. Patriarch of Constantinople, Nicolas Mysticus, did the same. In such a predicament, Symeon begged Pope John X (914-928) to send him an imperial crown and to recognize the head of the Bulgarian church as Patriarch. Naturally, Symeon had to promise to recognize the papal primacy in the Church. John X accepted Symeon`s request and sent a solemn mission to Bulgaria, headed by Cardinal Madalbertus and John, illustrious Duke of Cumae. The papal mission reached Bulgaria at the end of summer or during the fall of 926, carryng a crown and scepter with which they would crown Symeon as Bulgarian Emperor.

When the papal mission arrived in Preslav, Madalbertus started long negotiations with Symeon and the representatives of the Bulgarian church. Probably, Madalbertus convoked a church synod in Bulgaria as he later did in Split, in Croatia, on his way back to Rome in 928. The negotiations regarding ecclesiastical matters were successful, and Archbishop Leontius was created Patriarch in Preslav, still during Symeon`s reign.

Meanwhile, Symeon undertook imposing preparations for his crowing during the summer of 927. All of a sudden, he decided to wage a war against the Kingdom of Croatia.

The reason might have been that Tomislav received and protected the Serbs who were expelled by Symeon from Rascia. In all probability, however, the main reason was that Symeon, if crowned by Papal Legate, feared an attack from Byzantine Emperor supported by Tomislav. Emperor Romanus Lecapenus won the friendship of Tomislav some years previously, handing over the Byzantine Dalmatia to Tomislav and recognizing him as King of Croatia (Pope John X recognized Tomislav as King of Croatia in 925). During the summer of 926, Tomislav sent his troops to Italy to expel Saracens, from the city of Sipontus, which belonged to the Byzantine province of Langobardia. This event could have been a sufficient proof to Symeon that the Croats took the side of the Byzantine Emperor and that they would support him actively in the future. Therefore, when in the next spring Symeon sent a great army against the Croats, Bulgarians were met by Tomislav`s army in the mountainous region of Eastern Bosnia on May 27, 927.

According to Byzantine historian Constantine Porphyrogenitus, King Tomislav had an army of 160,000 soldiers (60,000 cavalry and 100,000 infantry). This was likely the greatest European army of the Middle Ages. The strength of Simeon's army is unknown but was probably as large as the Croatian army. The commander of the Bulgarian forces in this battle was Duke (Dux) Alogobotur.

The battle was a military catastrophe for the Bulgarians. According to many Byzantine and Russian historians (Joannes Zonaras, Constantine Porphyrogenitus, Georgius Cedrenus, Theophanes Continuatus, Chronicle of Nestor) Tomislav destroyed the Bulgarian army almost to a man. It is estimated that tens of thousands Bulgarian soldiers lost their lives on the battlefield.

When Symeon heard of the crush of his army, seven or eight days after the battle, he suffered a stroke and died about June 3, 927, without having been crowned with imperial crown brought by Madalbertus from Rome.

The Battle of the Bosnian Highlands was probably one of the greatest and bloodiest single-day battles in history and marked the end of Bulgarian expansion in the Balkans.