borders, securing as well the main communication between Frankish possessions in Bavaria and Pannonia. Younger stem duchy In his 817 Ordinatio Imperii, Charlemagne's son and successor Emperor Louis the Pious tried to maintain the unity of the Carolingian Empire: while imperial authority upon his death was to pass to his eldest son Lothair I, the younger brothers were to receive subordinate realms. From 825 Louis the German styled himself "King of Bavaria" in the territory that was to become the centre of his power. When the brothers divided the Empire by the 843 Treaty of Verdun, Bavaria became part of East Francia under King Louis the German, who upon his death bequested the Bavarian royal title to his eldest son Carloman in 876. Carloman's natural son Arnulf of Carinthia, raised in the former Carantanian lands, secured possession of the March of Carinthia upon his father's death in 880 and became King of East Francia in 887. Carinthia and Bavaria were the bases of his power, with Regensburg as the seat of his government. Due mainly to the support of the Bavarians, Arnulf could take the field against Charles in 887 and secure his own election as German king in the following year. In 899 Bavaria passed to Louis the Child, during whose reign continuous Hungarian ravages occurred. Resistance to these inroads became gradually feebler, and tradition has it that on 5 July 907 almost the whole of the Bavarian tribe perished in the Battle of Pressburg against these formidable enemies. During the reign of Louis the Child, Luitpold, Count of Scheyern, who possessed large Bavarian domains, ruled the Mark of Carinthia, created on the southeastern frontier for the defence of Bavaria. He died in the great battle of 907, but his son Arnulf, surnamed the Bad, rallied the remnants of the tribe in alliance with the Hungarians and became duke of the Bavarians in 911, uniting Bavaria and Carinthia under his rule. The German king Conrad I unsuccessfully attacked Arnulf when the latter refused to acknowledge his royal supremacy. Luitpoldings and Ottonians The Carolingian reign in East Francia ended in 911 when Arnulf's son, King Louis the Child, died without heirs. The discontinuation of the central authority led to a new strengthening of the German stem duchies. At the same time, East Francia was exposed to the rising threat from Hungarian invasions, especially in the Bavarian March of Austria (marchia