Editing Louis the Pious (section)

===Frontier wars===
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[[File:Louis le Pieu denier Sens 818 823.jpg|right|thumb|Louis on a ''[[denarius]]'' from [[Sens]], 818–823]]
At the start of Louis's reign, the many tribes—[[Danes (Germanic tribe)|Danes]], [[Obotrites]], [[Slovenes]], [[Bretons]] and [[Basques]]—which inhabited his frontierlands were still in awe of the Frankish emperor's power and dared not stir up any trouble. In 816, however, the [[Sorbs]] rebelled and were quickly followed by [[Slavomir (Obotrite prince)|Slavomir]], chief of the Obotrites, who was captured and abandoned by his own people, being replaced by Ceadrag in 818. Soon, Ceadrag too had turned against the Franks and allied with the Danes, who were to become the greatest menace to the Franks in a short time.

A greater Slavic menace was gathering on the southeast. There, [[Ljudevit (Lower Pannonia)|Ljudevit]], duke of [[Slavs in Lower Pannonia]], was harassing the border at the [[Drava]] and [[Sava]] rivers. The [[margrave of Friuli]], [[Cadolah]], was sent out against him, but he died on campaign and, in 820, his margravate was invaded by Slovenes. In 821, an alliance was made with [[Borna (duke)|Borna]], duke of the [[Dalmatia]], and Liudewit was brought to heel. In 824 several Slav tribes in the north-western parts of [[Bulgaria]] acknowledged Louis's suzerainty and after he was reluctant to settle the matter peacefully with the Bulgarian ruler [[Omurtag of Bulgaria|Omurtag]], in 827 the Bulgarians attacked the Franks in the [[March of Pannonia]] and regained their lands.<ref name=Collins1991>{{cite book |last=Collins |first=Roger |date=1991 |title=Early Medieval Europe 300–1000 |publisher=Palgrave Macmillan |pages=318–330 }}</ref>

On the far southern edge of his great realm, Louis had to control the Lombard [[List of dukes and princes of Benevento|princes of Benevento]] whom Charlemagne had never subjugated. He extracted promises from Princes [[Grimoald IV of Benevento|Grimoald IV]] and [[Sico of Benevento|Sico]], but to no effect.

On the southwestern frontier, problems commenced early when c. 812, Louis the Pious crossed the western Pyrenees 'to settle matters' in Pamplona. The expedition made its way back north, where it narrowly escaped an ambush attempt arranged by the [[History of the Basques#Early Middle Ages|Basques]] in the pass of Roncevaux thanks to the precautions he took, i.e. hostages. [[Seguin I of Gascony|Séguin]], duke of [[Duchy of Gascony|Gascony]], was then deposed by Louis in 816, possibly for failing to suppress or collaborating with the Basque revolt south of the western Pyrenees, so sparking off a Basque uprising that was duly put down by the Frankish emperor in Dax. Seguin was replaced by [[Lupus III Centule of Gascony|Lupus III]], who was dispossessed in 818 by the emperor. In 820 an assembly at [[Quierzy-sur-Oise]] decided to send an expedition against the Cordoban caliphate (827). The counts in charge of the army, [[Hugh of Tours|Hugh]], count of [[Tours]], and [[Matfrid]], count of [[Orléans]], were slow in acting and the expedition came to naught.