The Avars were a people of Turko-Mongolian origin related to the Huns who had been an important power in the European heartland since the sixth century. Aware of the threat these fierce, swift horsemen posed to the security of his eastern borders, Charlemagne tried to negotiate a pact with the Avars which would keep them east of the Danube River.
The Avars would make no agreement, and they did not hesitate to make frequent attacks on Frankish abbeys and monasteries. Charlemagne led a campaign against the raiders in 771, but he failed to reach the Avar citadel called the Ring, a legendary stronghold surrounded by nine walls and containing a fabulous treasure.
It was Prince Pepin who broke through the Avar defenses in 795, while the king was engaged in repelling Slavic tribes near the Baltic Sea. With the assistance of an advisor named Eric, Pepin led the Lombard army north from Friuli. In the region between the Sava and Drava rivers he dealt the enemy repeated defeats and also managed to make secret agreements with many Avar leaders which accelerated his progress towards the Ring. He reached the nine walls, stole the treasure and removed it to Charlemagne’s court.
The king was immensely encouraged by his son’s victory and urged Pepin to march against the Avars again to complete their destruction. In 796, Pepin’s Lombards defeated the final Avar strength on the banks of the Theiss River, and the nine walls of the Ring were totally destroyed.