The Hungarians invaded the Duchy of Bavaria in late June or early July 955 with 8,000–10,000 horse archers, infantry, and siege engines, intending to draw the main German army, under Otto I, into battle in the open field and destroy it.

As Otto I approached Augsburg on 10 August, a Hungarian surprise attack destroyed the Duchy of Bohemia rearguard legion.

The German heavy cavalry defeated the lightly armed and armored Hungarians in close combat, but the latter retreated in good order.

The most important source is a monograph commissioned by Ulrich of Augsburg, which describes the series of actions from the German point of view.

[2] In 947, Berthold, Duke of Bavaria, a competent military leader, died and was succeeded by Henry I, brother of King Otto I.

[4] In 952, Otto put Italy under the protection of the Bavarian army, and westward invasions by the Magyars stopped temporarily.

Harold was blinded and exiled to Tyrol, while his wealth was taken by Henry's vassals, but this upset many more Bavarian counts, who took up arms against the king.

Much of the city had already burned down, however its defenders long endured bombardment by Otto's siege engines before surrendering due to hunger, as no relief arrived.

The internal situation hardly improved after Otto's defeat of the rebellion, as the nephews of Prince Hermann of Saxony frequently raided the duchy, allying with Polabian principalities.

[7] In early July Otto received Hungarian legates, who claimed to come in peace, but who the Germans suspected were actually assessing the outcome of the rebellion.

[14] The battle took place six weeks after the first report of an invasion, and historian Hans Delbrück asserts that they could not have possibly made the march in time.

On previous occasions, in 932 and 954 for example, there had been Hungarian incursions that had invaded the German lands to the south of the Danube, and then retreated back to their native country via Lotharingia, to the West Frankish Kingdom and finally, through Italy.

That is to say, a wide sweeping U-turn that initially started westward, then progressed to the south, and then finally to the east back to their homeland; and thus escaping retribution in German territory.

[20] After admitting that this tactic doesn't work, a major action took place on 8 August at the eastern gate, which the Magyars tried to storm in large numbers,[1] suspecting that it has weak defense because of its difficult accessibility.

Next day, when the fights barely started they were informed by the traitor Berchtold of Risinesburg that Otto I deployed his troops near.

[2][14] As the Hungarians departed, Count Dietpald of Dillingen used the opportunity to lead soldiers to Otto I's camp during the night.

[23][24] The eighth division, commanded by Otto I, and slightly larger than the others, included Saxons, Thuringians, and the King's personal guard, the legio regia.

Not only do horses require a large area to graze, but training them to be comfortable in battle takes a significant amount of time.

[8] It's likely that Otto and Ulrich had communicated in the previous days, and that's why the king knew that the city needed a relief force quickly.

A legion of Swabians was commanded by Burchard III, Duke of Swabia, who had married Otto I's niece Hedwig.

A contingent of Hungarian horse-archers crossed the river west of Augsburg and immediately attacked the Bohemian legion from the flank.

According to these historians, while the infantry approached the center of the Magyar formation, Conrad's cavalry, posted on the left wing and protected on its flank from nearby cliffs, would stay out of range of the Hungarian archers but would also attempt to draw them more to their right.

Furthermore, because of their heavy equipment, Otto I's men were no doubt more affected by the stifling heat than their lightly armored opponents.

Simply put, the King and his men were in no position to pursue and destroy the Magyars that day, leaving the initial battle a draw.

The Magyars were also known to pull off feigned retreats, when they would lure their opponents into more advantageous positions, like open fields, then they would turn and defeat them.

[33][38] The majority of these fortifications had been built and fortified during the reign of Otto I's father, Henry I of Saxony, as part of his defense-in-depth strategy against enemy invaders.

[39] If these had not been in place, it is very likely that the Hungarians could have completed an orderly retreat once the floodwaters receded and the Battle of Lechfeld would have remained a draw.

[28] One of Otto's allies, the bishop of Cremona, claimed that the victory at Lechfeld left the Hungarians so cowed that they would not "dare to mutter.

In addition, Otto I did not launch any further military campaigns against them; their leader Fajsz was dethroned following their defeat and succeeded as Grand Prince of the Hungarians by Taksony.

[49] Paul K. Davis writes, the "Magyar defeat ended more than 90 years of their pillaging western Europe and convinced survivors to settle down, creating the basis for the state of Hungary.