The most important source for the battle is the 16th-century chronicle of the Bavarian Renaissance humanist, historian, and philologist Johannes Aventinus (Annalium Boiorum VII), (1477–1534), which contains the most comprehensive descriptions.

During the last Hungarian attacks against Bavaria, Luitpold's forces defeated some of their units in minor battles, including Laibach (901) and Fischa River (903).

In these cases, the following principles of warfare were used with great success: While the Hungarians won many battles against European forces after 910 (915: Eresburg; 919: Püchen, somewhere in Lombardy; 921: Brescia; 926: somewhere in Alsace; 934: W.l.n.d.r.

The commanders resorted to draconian measures to motivate the soldiers to fight; for example, during the Siege of Augsburg in 955, the Hungarian warriors were driven to attack the walls with scourges.

Based on Aventinus' chronicle, the Bavarian political, military, and clergy gathered on June 15, 907, at Ennsburg to plan the campaign,[29] concluding that "the Hungarians must to be eliminated from Bavaria.

"[30][31] At this time, Bavaria included Pannonia, Ostmark, east from the river Enns, and probably the old lands of the Great Moravia (now the western part of Slovakia).

[3] The de facto commander, Margrave Luitpold, let him accompany them as far as the St. Florian Monastery, located between the rivers Enns and Traun, on the border between Bavaria and the Principality of Hungary.

[3] Contemporary German sources state the Bavarian leaders had great conceit and presumption,[34] probably due to killing Kurszán in 904 and their minor victories.

[18] This is also evidenced by how the German army, in addition to political and military leaders (Prince Sieghard, a number of counts; among them were Meginward, Adalbert, Hatto, Ratold, and Isangrim), brought some of the most influential clergy members from East Francia (Dietmar I, Archbishop of Salzburg, the Chancellor of the Realm; Zacharias, Bishop of Säben-Brixen; and Utto, Bishop of Freising), along with a large number of priests.

However, it is certain that he did not die during the battle because his duties as sacred grand prince, Kende, were only spiritual,[36] preventing him from participating in military or political actions.

A fleet under Prince Sieghard and the counts Meginward, Hatto, Ratold, and Isangrim was stationed on the Danube to ensure communication among these groups[37] and to transport food and heavily armored footsoldiers as an auxiliary force to be deployed if one of the Bavarian army corps was attacked.

[38] This is similar to the strategy Charlemagne used in his famous campaign against the Avars in 791, where he divided his army in exactly the same way, with troops marching on both sides of the Danube, and a fleet to ensure they remained connected.

For example, the Scythians against Darius I and Alexander the Great, or the Avars against Charlemagne,[46] and more than 100 years after the Battle of Pressburg (1030), Hungary's first king, Stephen I, defeated the invasion of the German Emperor Conrad II using scorched earth, causing famine among the enemy soldiers.

[47] In the same way, King Andrew I of Hungary defeated another German invasion led by Emperor Henry III in 1051 using the same scorched earth tactic.

The constant harassment by the Hungarian mounted archers slowed the movement of the Bavarian army even more, forcing them to stop to defend themselves, thus demoralizing them prior to battle.

In the end, when the decisive moment came, when, thanks to the relentless Hungarian attacks and misleading tactics and psychological warfare, the battle order and the control of the commanders were totally lost and the soldiers were completely demoralized, tired, and losing any hope, the Hungarians suddenly attacked them from front, back, and sides, encircling and annihilating the southern corps led by Archbishop Dietmar.

Nevertheless, this first day of the battle brought with it the slaughter of the southern corps of the attacking army, including Archbishop Dietmar, the bishops Utto of Freising and Zachariah of Säben-Brixen, and the abbots Gumpold, Hartwich, and Heimprecht.

Aventinus writes nothing about how they managed to attack the fleet, and he points only to the ease of the Hungarian victory and the paralyzing terror of the Germans, who could do nothing to defend themselves.

[62] Although there is nothing known about how the Hungarians accomplished this difficult task - destroying the Bavarian fleet - easy, it can be outlined that they did it in the following way: the Magyar army, aligning on both the shores of the Danube, shot burning arrows on the ships, setting them on fire, like they did so many times during the period of the Hungarian invasions of Europe, when the Magyars set many cities on fire by shooting, from great distance, burning arrows on the roofs of the houses behind the city walls, like they did with the towns of Bremen (915),[63] Basel (917),[64] Verdun (921),[24] Pavia (924),[65] and Cambrai (954).

We can presume that those Bavarians who wanted to escape from the burning ships jumped in the water, and a part of them drowned, and those who arrived at the shore were killed by the Hungarians.

As a result, the majority of the Bavarians from the ships, together with their commanders, Prince Sieghard, counts Meginward, Hatto, Ratold, and Isangrim, died on the last day of the battle.

The Bavarian population rushed to big cities like Passau, Regensburg, Salzburg, or in the Alps mountains in woods and marshes to escape the punitive Hungarian campaign, which devastated Bavaria and occupied new territories in the eastern parts of the duchy, pushing Hungary's borders deep in Bavarian territory over areas west of the Enns river, the former border.

[81] The majority of the historians,[3][82][83][84] relying on the most detailed account of the battle, Annalium Boiorum VII of Johannes Aventinus, written in the 16th century, which presents the fights on the northern the southern shores of the Danube (Danubium) river and on the river itself, near the city of Vratislavia (Pressburg), involving a Bavarian fleet that came on the Danube, accept the location of the battle in the surroundings of today's city of Bratislava.

[89] They occupied St. Florian Monastery and other places near the Enns River, and the people ran away to cities like Salzburg (Iuvavia), Passau (Bathavia), Regensburg (Reginoburgium), or in the mountains in woods, marshes, or fortresses.

[85] Then Aventinus refers to the fact that in the Hungarian army, women could be warriors too, which fought in the war, believing that they would have in the afterlife as many servants as they would kill in the battle.

[92] After that, the Hungarians crossed the river Enns, swimming with their horses (amnem equis tranant), in southern Bavaria and plundered the cities and monasteries they found on their way, occupying and burning Schliersee, Kochel, Schlehdorf, Polling, Dießen am Ammersee, Sandau, Thierhaupten, etc.

On the Hungarians way back home, the Bavarians, who wanted to take their spoils away, tried to ambush them at Lengenfeld, at the road that leads to the village, but the Magyars defeated them, put them down, and swept them away.

[97] The Hungarian victory forced the new Bavarian prince, Luitpold's son, Arnulf, to conclude a peace treaty, according to which the prince recognized the loss of Pannonia (Transdanubia) and Ostmark, the river Enns as a borderline between the two political entities, paid tribute,[98] and agreed to let the Hungarian armies, which went to war against Germany or other countries in Western Europe, pass through the duchies lands (despite this agreement, Arnulf did not feel safe, strengthened the Bavarian capital, Regensburg, with huge walls, strengthened the Bavarian capital, Regensburg, with huge walls, and organized an army that, he hoped, he could defeat the Hungarians,[95] but he never had the courage to turn definitively against them).

[104] In the long run, thanks to their victory at Pressburg, the Principality of Hungary defended itself from the ultimate objective of the East Francian and Bavarian military, political, and spiritual leaders: the annihilation, giving a categorical response to those foreign powers who planned to destroy this state and its people.

We can say that thanks to this victory, Hungary and the Hungarians today exist as a country and nation because, in the case of a German victory, even if they hadn't kept their promise, sparing the Hungarians from annihilation or expulsion, without an independent state and church, the Magyars hadn't kept their promise, sparing the Hungarians from annihilation or expulsion, without an independent state and church, the Magyars would have had little chance to organize themselves as a Christian nation and culture, and probably they would have shared the fate of other nations or tribes that were not Christian when they had been conquered by the Carolingian and its successor, the Holy Roman Empire: the Avars, the Polabian Slavs, or the Old Prussians: disparition, or assimilation in the German or Slavic populations.