The German–Hungarian War took place between two neighboring realms, the Holy Roman Empire and the Kingdom of Hungary, in the summer of 1030, when emperor Conrad II launched a large-scale invasion to subjugate Hungary. The emperor, however, failed due to the scorched earth tactics used by the Hungarians. Their king Stephen I, in response, led a successful retaliatory campaign into Austrian territory. Peace was restored after Conrad had ceded the lands between the rivers Leitha and Fischa to Hungary in the summer of 1031. This war was the Holy Roman Empire's first attempt to annex Hungary's sovereignty, which endeavor accompanied the relationship between the two countries until the end of the 11th century.
Background
German–Hungarian relations
With emperor Otto III's approval, Stephen I was crowned as the first Christian king of Hungary on Christmas Day, 1000. Otto III's successor, Henry II, was Stephen's brother-in-law by Stephen's marriage to Henry's sister Gisela, furthering the friendly relationship between the Holy Roman Empire and Hungary, which ensured that the western borders of Hungary experienced a period of peace in the first decades of the 11th century. Even when Henry II's discontented brother, Bruno, sought refuge in Hungary in 1004, Stephen preserved the peace with Germany and negotiated a settlement between his two brothers-in-law. Stephen's alliance with the Holy Roman Empire brought him into a war with Poland lasting from around 1015 until 1018. The German–Hungarian alliance did not mean political subjugation or vassal relationship for the new Christian kingdom. For instance, Stephen established at least one archbishopric, six bishoprics and three Benedictine monasteries, leading the Church in Hungary to develop independently from the ecclesiastical organization of the Holy Roman Empire. Henry did not question Hungary's independence, and Stephen did not intervene in German internal disputes, except when he mediated between the emperor and Bruno.
Emperor Henry II died on 13 July 1024. He was succeeded by a distant relative, Conrad II, the first emperor from the Salian dynasty. Under Conrad II, the German–Hungarian relations quickly turned hostile as Conrad pursued a more aggressive policy regarding eastern Europe. Perhaps Bishop Bruno of Augsburg, the brother of the deceased Henry, was a driving force behind this change. Conrad's "ostpolitische Konzeption", as German historiography refers to it, sought to conquer Bohemia, Poland and Hungary in order to establish and then maintain the Holy Roman Empire's hegemony in East-Central Europe. It was a sign of the emerging confrontation that Conrad II expelled the Venetian doge Otto Orseolo, the husband of Stephen's sister Grimelda from Venice in 1026. Conrad also persuaded the Bavarians to accept his own minor son, Henry, as their duke in 1027, although Stephen's son, Emeric of Hungary, had a legitimate claim to the Duchy of Bavaria through his mother. With Conrad's step, the frequent conflict between the German emperor and the Bavarian duke ceased, and Hungary became bordered by a hostile great power. Emperor Conrad planned a marriage alliance with the Byzantine Empire and dispatched one of his advisors, Bishop Werner of Strasbourg, to Constantinople. The bishop presented himself as a pilgrim, but Stephen, who had been informed of his actual purpose, which was completely contrary to Hungary's security policy interests, refused to let him enter the country in the autumn of 1027.
Reasons for Conrad's attack
Historical records
At this same time, dissensions arose between the Pannonian nation and the Bavarians, through the fault of the Bavarians. And, as a result, King [Stephen] of Hungary made many incursions and raids in the realm of the Norici (that is, of the Bavarians).
— Wipo, The Deeds of Conrad II
A contemporary author, Wipo of Burgundy, who was the court chaplain of Conrad II narrates the events in his biography of the emperor titled Gesta Chuonradi II imperatoris. Wipo wrote and presented his work to Conrad's son Henry III in 1046, shortly after the latter's coronation. Wipo narrates that the Bavarians incited skirmishes along the common borders of Hungary and the Holy Roman Empire in 1029, causing a rapid deterioration in relations between the two countries. The priest blamed the Bavarians for the conflict, which led Stephen's troops to continuously invade the duchy, primarily its frontier march, the Margraviate of Austria (Ostmark) for raids. During these campaigns, the Hungarians obtained numerous spoils. The emperor launched his war in retaliation for this. Although Wipo suppressed many facts, he insisted on objectivity, and the Hungarians appear in the role of victims or as the attacked party due to the provocations of the Bavarians. Wipo also shows sympathy for Stephen I, who he claims is protected by God.
Wipo's contemporary Aloldus de Peklarn, the court chaplain of Adalbert, Margrave of Austria, who also participated in the war, writes that Conrad II and Stephen I took up arms against each other over the Bavarian succession issue. Aloldus' work was preserved by the 12th-century chronicler Ortilo de Lilienfeld, which itself became part of the compilation of 18th-century historian Chrysostomus Hanthaler. The Cistercian friar, however, added to or even falsified the texts on numerous occasions, so the authenticity of Aloldus is uncertain. Benedictine scholar Hermann of Reichenau writes that Emperor Conrad "had been at odds with the King of the Hungarians for a long time". Another 12th-century source, the Kaiserchronik claims that Stephen "did many evils against the empire", as a result of which, encouraged by the surrounding princes, Conrad launched his campaign.
The 15th-century Humanist scholar Georgius Merula claims that Conrad II attacked the Hungarians because they were inciting the Italian peoples to revolt and defect against the emperor by promising them help. The 16th-century Humanist historian Johannes Aventinus writes that the envoys of Stephen and Gisela were present at the imperial diet of Regensburg in July 1027, where they announced Emeric's claim to the Duchy of Bavaria. After Conrad refused their demand, they declare war on the emperor, then returned home. While several 19th-century German historians accepted this data as reliable, Hungarian historian Gyula Pauler refused Aventinus' report saying it contradicts contemporary sources. Henrik Marczali argued that the young Henry, who was appointed Duke of Bavaria, diligently played a role in the German–Hungarian peace process (see below), so it is unlikely that the war broke out over the possession of Bavaria. Other historians, such as Bálint Hóman and György Györffy, however, somewhat accepted Aventinus' data as reliable. Gyula Kristó considered that although contemporary sources do not mention the Hungarian claim, Conrad's quick move to appoint Henry perhaps suggests this. Iván Kis argued that Aventinus highlighted Emeric's claim among the several reasons that sparked the war because he could thus accuse the Hungarian side of being responsible for the outbreak of the conflict.
Modern historiography
Several theories have been formulated in Hungarian historiography as to the specific reason for Conrad's invasion to Hungary. 19th-century historian Mihály Horváth considered that Stephen I joined that anti-imperial alliance which centered around Pope John XIX (however, by 1027, the pope became an ally of Conrad). Accepting the account of Johannes Aventinus, historians László Szalay and Antal Pór argued that the war broke out over the possession of the Duchy of Bavaria. Henrik Marczali saw the cause of the conflict in the unsettled border relations between the two realms. Bálint Hóman considered that Conrad decided to go on the campaign because he feared that the Venetian opposition, which aimed to overthrow the Doge of Venice, Pietro Barbolano, who had completely submitted to him, would, with the support of Stephen, appoint Otto Orseolo, who was in exile in Constantinople, or his son, Peter, who was being raised at the Hungarian court, as the doge of Venice. Gyula Pauler, Albin F. Gombos and András Borosy argued that the main reason for the war was to be found in Conrad's personality; the new German ruler wanted to conquer, taking advantage of the dominance of his empire. György Györffy argued that Conrad II, abandoning the peace-oriented diplomacy and the "universal Roman" aspirations of his predecessors, embarked on a new "German imperial" policy, using tools of military power. Attila Zsoldos emphasized that instead of establishing peaceful cooperation between Christian states, Conrad saw the establishment of German hegemony as a means of securing imperial power.
German historiography also dealt with the investigation of the causes of the war. 19th-century historian Max Büdinger found the specific reason in the Stephen's aforementioned refusal of the imperial envoy to enter Hungary. Wilhelm von Giesebrecht considered that the expansion of Stephen at the expense of the Poles created a hostile attitude towards the Hungarians in Conrad II. Harry Bresslau added that Stephen was prompted to go to war by Conrad's actions against his ally, Otto Orseolo.
The war
German invasion
Disturbed on this account Emperor Conrad came upon the Hungarians with a great army. But King [Stephen], whose forces were entirely insufficient to meet the Emperor, relied solely on the guardianship of the Lord, which he sought with prayers and fasts proclaimed through his whole realm. Since the Emperor was not able to enter a kingdom so fortified with rivers and forests, he returned, after he had sufficiently avenged his injury with lootings and burnings on the borders of the kingdom.
— Wipo, The Deeds of Conrad II
Conrad II prepared for war in the early weeks of summer 1030. The emperor has spent the night in the Benedictine abbey of Niederaltaich near Regensburg on 21 June. Conrad organized the campaign and gathered his army here, summoning the troops throughout from Lotharingia to Ostmark. Armies were mobilized from many provinces of the Holy Roman Empire. Meinwerk, the Bishop of Paderborn, Henry II, Count of Luxembourg and Adalbert, Margrave of Austria were present leading their respective contingents. The 15th-century chronicler Thomas Ebendorfer incorrectly identified Ernest as commander of the Austrian troops. It is possible that Bretislav, the son of Oldřich, Duke of Bohemia and Conrad's vassal also took part in the campaign commanding the Bohemian and Moravian auxiliary troops.
The offensive under the personal command of the emperor against Hungary was taken in the first days of July 1030. The German army probably followed the military and trade route that was also used by pilgrims passing through Hungary, and later by the crusaders. The line of offensive is unclear except for the fact that Conrad had fighting units near the river Fischa. The German army was able to advance to the flow of Rába under difficult conditions. Hermann of Reichenau writes that Conrad "overran the Pannons [Hungarians] and as long as the swamps and rivers let him to do this destroyed everything in line of the River Rába". Both Wipo and Hermann highlight the effective use of natural obstacles as part of Hungarian defense. The legenda maior of Stephen I mentions that the Hungarian king had time to prepare; summoned the royal council of bishops and nobles, ordered a nationwide fast and prayer, and prepared a war plan. It is plausible that the king's son Emeric, based on his age, also fought in war.