Guduscani
The Guduscani or Goduscani were a tribe whose location and origin on the territory of early medieval Croatia remains a matter of dispute. According to different hypotheses, they were a tribe or clan of Croat, Slavic, Avaric or Gothic origin that was located around present-day Gacka, between upper Kupa River and the Dalmatian coast, or that were inhabitants around the river Guduča near the Bribir region.
Etymology
They are mentioned three times in the Frankish Annals and twice in Vita Hludovici. Petar Skok and Radoslav Katičić derived their ethnonym from Proto-Slavic *gъd-, similar to Proto-Prussian gude in the meaning of "forest". Skok, and Petar Šimunović, also derived it from Proto-Slavic *gadъ, "snake", or *gatъ, "gap, depth, dam".Constantine VII mentioned in his work De Administrando Imperio a županija in Croatia in the 10th century called "Gūtzēkă", which is translated as Gacka. Scholars tried to connect toponym Gacka with the ethnonym of the Guduscani, but although it is not certain that the toponym got its name from the ethnonym, the Latin suffix "-anus" shows that the name Guduscani merely had territorial meaning of the "inhabitants of Gacka".
The hypothetical derivation from the toponym of Roman city of Guduscum is rejected by now because such a toponym never existed. The theory relating their name to the name of Goths is problematic because the suffix indicates that the ethnonym originates from name of a place and not people.
History
In the Frankish Annals, the Guduscani are mentioned as allies to the Carolingians, and the Duke Borna is mentioned as "dux Dalmaciae", "dux Dalmatiae et Liburniae" and "dux Guduscanorum". However, there exist different semantic readings of the source, some saying that Borna was the duke of Guduscani, or of Guduscani and Timočani or a separate duke from both of them.Borna seemingly was the first titled duke, i.e. prince of Guduscani, which indicates that the Guduscans initially could have been the temporary basis of Borna's authority and could have occupied a much larger territory from Bribir in Dalmatia to Gacka in Lika, south of Lower Pannonia. The old consideration that the Guduscani originated from the territory of Moesia and that together with the Timočani became allies of the Franks is disputable due to lack of evidence and arguments.
In 818 they were part of an envoy of Borna sent with the other South Slavic tribes of Timočani and Praedenecenti to the court of Louis the Pious in Herstal. Some scholars also related them to the Khashānīn mentioned by Al-Masudi. In 819 alongside Borna fought against Ljudevit, the Duke of the Slavs in Lower Pannonia. They were part of the army of Borna against Ljudevit at the Battle of Kupa but deserted before the battle. Borna conquered their lands again upon returning from the battle.