From the mid 11th century, the Kingdom of Hungary had been expanding its territory and influence southwards, with a view to annexing the regions of Dalmatia and Croatia.

In 1163, under the terms of an existing peace treaty, King Stephen III's younger brother Béla was sent to Constantinople to be raised under the personal tutelage of the emperor himself.

But in 1167, King Stephen refused to give Manuel control of the former Byzantine territories allocated to Béla-Alexios as his appanage; this directly led to the war that ended with the Battle of Sirmium.

The main battle line was shielded by a screen of horse archers – Turks and Cumans – and some western mercenary knights, who had made up the vanguard of the army.

[15] The left wing, which had been the second division on the march, was composed of regular Byzantine and allied units arrayed in four taxiarchies or 'brigades' under Demetrios and George Branas, Tatikios Aspietes[16] and Kogh Vasil.

[19] The Hungarian commander, Dénes, count of Bács (called Dionysios in Byzantine sources), drew his army, which included German allies,[20] up in three divisions in a single broad battle line.

[22] The battle commenced with the Byzantine horse archers moving forward to skirmish with, and harry, the opposing lines and thereby goad them into mounting a charge, before which they were to retire.

The Byzantine left wing, with the exception of the brigades led by Kogh Vasil and Tatikios, was immediately pushed back and broke, possibly in feigned flight, towards the river, where it quickly reformed.

Andronikos Lampardas then led an attack on the troops around the Hungarian commander and brought them to a halt; a deadly melee ensued with the Byzantine heavy cavalry resorting to the use of their fearsome iron maces.

[27] The Hungarians sued for peace on Byzantine terms and recognised the empire’s control over Bosnia, Dalmatia, Croatia south of the Krka River as well as the Fruška Gora.