The Guduscani (Croatian: Gačani) were an indetermined tribe on the then western border with the Avar Khaganate, around present day Gacka (Lika), between upper Kupa river and the Dalmatian coast. It has been assumed, that they were part of the Vandals, Goths[1] or Lombards.
In the Frankish Annals, the Guduscani are mentioned as allies to the Carolingians, the Duke Borna is mentioned as "dux Dalmaciae", "dux Dalmatiae et Liburniae" and "dux Guduscanorum". Borna had conquered the Guduscani, who were an independent tribe.
In 818 they were part of an envoy of Borna sent with the South Slavic tribe of Timočani to the court of Louis the Pious in Herstal. In 819 Ljudevit Posavski conquered their lands and pushed Borna to Vinodol.
They were part of the army of Borna against Ljudevit Posavski at the Battle of Kupa but deserted before the battle. Borna conquered their lands again upon returning from the battle.[2]
The Guduscani were later described by Constantine VII (905-959), who mentioned them as part of a state of White Croatia, its capitol Krakow including parts of Bohemia, Slovakia and land of later Poland.