In 818 Ljudevit sent his emissaries to
Emperor Louis in
Heristal. They described the horrors conducted by
Margrave Cadolah of Friuli (800-819) and his men in
Pannonia, but the King of
Franks refused to make peace. Ljudevit raised a rebellion against his Frankish rulers in 819 after he was seriously accused by the Frankish court. The
Emperor Louis the Pious (814-840) sent Cadolah to quell the rebellion. The Frankish Frontier forces led by Cadolah have raided the land and tortured the population, most notably the children. As the Pannonian Slavs were amassing forces, so did the
Franks led by Cadolah return in 819. But the Frankish forces were soon defeated; and Cadolah himself had to retreat back to his home
Friuli, where soon he died of disease. In July 819 on the Council in
Ingelheim Ljudevit's emissaries offered truce conditions, but Emperor Louis refused; demanding more concessions to him. Ljudevit started to gather allies for his plight. His original ally was
Duke Borna (Dux Dalmatiae et Liburniae) - the leader of the
Guduscani (Gačani), but the Frankish ruler had promised Borna that he would make him
Prince of Pannonia if he helped the Franks to crush Ljudevit's rebellion; so Borna accepted. Ljudevit found assistance among the
Carantanian and
Carniolan Slavs who, as neighbours of the margravate of
Friuli, were jeopardized the same as the Pannonians. The
Timočani (living around the valley of
Timok) also joined him, because they were jeopardized by the neighbouring
Bulgars. The Franks sent a large army led by the new
Margrave of Friuli, duke
Baldric of Friuli to meet Ljudevit in autumn, the same year while he was conscripting more Carantanian troops along the
Drava river. The Frankish forces had numerical advantage, so they pushed Ljudevit and his men from Carniola across the Drava. Ljudevit had to fall back to central parts of his realm. Baldric didn't chase Ljudevit, since he had to pacify the Carantanians. Borna moved with Ljudevit's father-in-law Dragomuž and their forces from the south-west. At the heat of the
Battle of Kupa, his own Guduscani abandoned Borna and crossed to Ljudevit's side; while Dragomuž was killed. Borna escaped from the battlefield with the help of his bodyguards. Ljudevit seized the opportunity and breached into and raided
Dalmatia in December. Borna was too weak, so the Dalmatians defended themselves through sneaky tactics and used
attrition as their best ally to exhaust the Pannonian forces. Harsh winter came to the hill areas, forcing Ljudevit to retreat. According to Borna's reports to the Frankish Emperor, Ljudevit suffered heavy casualties: 3,000 soldiers, over 300 horses and much food. ==War continues==