During the reign of Justinian I, in the mid-6th century, the Avars that stayed in Dobrudja had demanded Byzantine territory, but refused the offer of Lower Pannonia. After Justin II discontinued the tribute to the Avars, they marched on Eastern Frankish territory. The Royal Frankish Annals makes mention of a Wonomyrus Sclavus active in 795. Eric, Duke of Friuli, sent Vojnomir with his army into Pannonia, between the Danube and Tisza, where they pillaged the Avars' dominions. The next year the Avars were defeated and Frankish power was extended further east, to the central Danube.
History
Initially, the Slavic counts were under Frankish suzerainty, part of Frankish Pannonia, and are known from Frankish primary sources. Ljudevit was mentioned in the Frankish Annals as Liudewitus, dux Pannoniae inferioris, having led an uprising against the Franks, joined by the Carantanians and other Slavic tribes. In 827, the Bulgars under Great Khan Omurtag invaded and conquered Lower Pannonia and parts of Frankish territories to the north. In 829 the Bulgars imposed a local Slavic prince, Ratimir, as the new ruler of Pannonia. His province is believed to have been the territory of Roman Pannonia Savia. In 838, nine years later, following the Bulgar conquest of Macedonia, the Danubian count Radbod, prefect of the East March, deposed Ratimir and restored Frankish rule in Pannonia. Ratimir fled the land, and the Franks next instated Slavic princes Pribina and Kocel as rulers of Pannonia. In the mid-9th century, Lower Pannonia was inhabited by a Slavic majority. Christian Avars were found in Lower Pannonia in 873.
Braslav was the Duke of Lower Pannonia between 884 and 896. His territory initially spanned between the Drava and Sava, which he held under the overlordship of Arnulf of Carinthia. He participated in the Frankish–Moravian War, and in 896 Arnulf handed over Pannonia to him in order to secure the Frankish frontier against the Hungarians, however, the Hungarians subsequently overran all of Pannonia and continued into Italy.
Aftermath
Following the rise of the Principality of Hungary in the mid 890s, no further Slavic rulers were recorded in the territory until the mid 920s when the Duke of CroatiaTomislav united the territory with Dalmatian Croatia to form the Kingdom of Croatia. There has remained a general uncertainty and dispute over the relationship between the Croatian and Hungarian kingdoms in the 10th and 11th century, with Croatian historian Ferdo Šišić and his followers assuming Tomislav of Croatia had ruled most of the area inhabited by Croats, including Slavonia, while the Hungarian historians Gyula Kristó, Bálint Hóman and János Karácsonyi thought the area between Drava and Sava belonged neither to Croatia nor to Hungary at the time, an opinion that Nada Klaić said she would not preclude, because the generic name "Slavonia" may have implied so.
