Background
Hungarian army in the XII. Century
After the coronation of St. Stephen and the foundation of the Christian state, the steppe style army and its organization changed. Hungary was divided into counties (comitatus) under an appointed count (comes) who represented royal power. In St. Stephen’s time, two-thirds (2/3) of the counties' territories were private properties of the king, or, more exactly, the royal family. These vast estates were the base of royal supremacy and unquestionable power for the next 250 years. The population of the royal estates were, theoretically, the property of the king (proprius). Of course, they were very different from the classical slaves.
The army was composed of contingents from the counties led by the count. These contingents fought:
- the soldiers of the royal estates led by the várjobbágyok (iobagiones castri) as officers. Their commander was the hadnagy (maior exercitus)
- free people living in the country; the richer fought personally, often with their personal retinue, the poorer armed together one soldier.
There were also privileged ethnic groups with their own leaders like the Seklers, the Petchenegs, the so-called Saracens (mostly muslim khwarezmians) and, later, the Cumans and the Saxons. The elite troops were the members of the royal retinue, the wealthiest barons, the foreign knights, their own retinues, and the rus mercenaries. (King Stephen organized his own varangian guard.)
The bulk of the Hungarian soldiers were some kind of hybrid cavalry. They wore leather armours, their main arms were  | Reconstruction of Bela's Face |
composite bow, lance, and sword (instead of saber). These troops were able to fight as horse archers or in melee. The rate of western style knights were low, they fought mainly in the royal retinue. The Seklers, Petchenegs and Saracens fought in traditional steppe way as horse archers.
The overall size of the full royal army was around 30 000 men (in foreign campaigns) and total manpower was 50 000 men.
The Conflict with the Byzantine Empire
The Rise of Byzantine military power under the Comneni caused rivalry between the empire and Hungary on the Balkans, although the the conflicts were limited until the time of Manuel I. Manuel’s main goal was reviving the ancient Roman Empire. And he shows uncommon interests in the affairs of Hungary. Some historians believe that this was caused by the simple fact that, through his mother (Piroska/St. Eirine), his grandfather was St. Ladislaus of Hungary. (In truth nobody knows what he really thought). All in all, Manuel frequently launched campaigns against Hungary and aided more anti-kings and pretenders. On the other hand, Hungary aided the Serbs against the Byzantines.
The emperor also found a diplomatic, dynastic way to unite Hungary with the empire. In 1163, according to the current peace treaty, Béla, the younger brother of king Stephen III, was sent to Constantinople to be raised under the personal tutelage of the emperor himself. As Manuel’s relative and the fiance of his daughter Béla (then Alexius), he became a despot (a newly created title for him), and, in 1165, he was named as an heir to the throne. He was also the heir of the Hungarian throne and that could have easily established a union between the two states.
But, in 1167, king Stephen still lived and he denied Manuel the territories of Béla's duchy. This caused war between Hungary and the Byzantine Empire, which was ended by the Battle of Zemun.
The Battle
Neither the king nor the emperor was personally present. The Hungarian army consisted of cca. 15 000 men and were aided by an Austrian contingent of knights. This army was led by count Dénes.
The Byzantine army was led by Andronicus Contostephanos and they had cca. 20 000 men. The Byzantine battle plan was made by emperor Manuel (after consulting with his astrologers) and Contostephanos was bound to it.
The first line of the imperial army was light cavalry with heavy cavalry on its flanks. The second line was heavy infantry reinforced with seldjuk archers, also with heavy cavalry on its flanks. The third line was the reserve: Serbian and Norman knights (mercenaries) with the general.
Dénes, the Hungarian general, focused all of his heavy cavalry (Hungarians and Austrians) to the first line of the center. On the flanks and on the second line of the centre were medium cavalry. There was no reserve and there was no infantry.
During the battle, the Hungarian center frontally attacked the byzantine light cavalry and its right wing pushed back the left wing of the Byzantine army. The Hungarian heavy cavalry simply trampled the Byzantine light cavalry, but was checked by the phalanx of the heavy infantry. Meanwhile, the Byzantine right defeated the Hungarian left wing and the Byzantine reserve, in a hard fight, stopped the Hungarian advance on their left wing. With the Byz  | Маnuel Komnenos |
antine victory on the wings and failure of the Hungarian centre, the battle was lost. It is said that, after the battle, the Byzantines collected 2000 armours from the battlefield. Byzantine sources also mentioned the superiority of the weapons of the imperial troops. When the lances broken, both Hungarians and Byzantines used swords, and when the swords chiped, the Byzantines used maces, but the Hungarians ran out of weapons.
With this victory the empire secured the newly seized territories and ended the war.
Aftermath
In 1169, Manuel’s son was born and the plan of the dynastic union under Béla was changed. Béla lost the title of despot (he became a caesar) and his engagement with Manuel’s daughter was broken. He married the half-sister of the empress: Anna (or Agnes) Chatillon of Antioch. (daughter of Raynald de Chatillon).
In 1172, he was invited to the throne of Hungary and, with Manuel's help, he became the king of Hungary as Béla III. Manuel and Béla remained close allies. After Manuel’s death, Béla launched a campaign to save Alexius II (and he recaptured the territories lost after Zemun). Gyula Moravcsik presumed that he tried to seize the imperial throne from Andronicus, but he failed by the sudden appearance of Isaac II.
Nevertheless Béla III was one of the most powerful and significant kings of the Arpad age. | 
