The County of Osona, also Ausona (Catalan: Comtat d'Osona, IPA: [kumˈtad duˈzonə]; Latin: Comitatus Ausonae), was one of the Catalan counties of the Marca Hispanica in the Early and High Middle Ages. It was based around the capital city of Vic (Vicus) and the corresponding diocese, whose territory was roughly the current comarca of Osona.
The ancient diocese of Osona was sacked by the Arabs in the mid eighth century (c. 750–755). Its reconquest by Christian powers began in 798; in that year Louis of Aquitaine ordered Borrell, a Goth, to enter the abandoned region and repair the castles of Vic, Cardona, and Casserès. Vic was in Frankish hands by 799. After the successful siege of Barcelona in 801, Borrell, already Count of Cerdanya and Urgell, received Osona as a countship from his liege lord, King Louis. On Borrell's death, Osona was granted to Rampon, Count of Barcelona. After the rebellion of 826, during which Guillemó and Aissó succeeded in taking it with help from the Emirate of Córdoba, Osona remained depopulated and outside of Frankish control until 879. It was considered to be part of the County of Barcelona throughout that period.
