Istria, the largest peninsula in the Adriatic…

Istria, the largest peninsula in the Adriatic Sea, located at the head of the Adriatic between the Gulf of Trieste and the Bay of Kvarner, had been pillaged after the fall of the Western Roman Empire by the Goths, the Eastern Roman Empire, and the Avars.

Annexed to the Lombard Kingdom in 751, it was subsequently annexed to the Frankish kingdom by Pippin III in 789.

Frankish commander Eric of Friuli had been killed in 799 on the border between Dalmatian Croatia and Carolingian Empire in the Siege of Trsat, a Croatian victory.

The Placitum of Riziano of 804 was held in the Parish of Risanum, or Rižan, which was a meeting between the representatives of Istrian towns and castles and the deputies of Charlemagne and his son Pepin.

The report about this judicial diet illustrates the changes accompanying the transfer of power from the Eastern Roman Empire to the Carolingian Empire and the discontent of the local residents. (Oto Luthar, ed. (2008). The land between: a history of Slovenia. Frankfurt am Main: Peter Lang. p. 100.)

Istria afterward has been successively controlled by the dukes of Carantania, Bavaria and by the patriarch of Aquileia.

The medieval Croatian kingdom had held only the far eastern part of Istria (the border is near the river Raša), but in the late eleventh century had lost it to the Holy Roman Empire.

The coastal areas and cities of Istria in the ninth century had come under Venetian influence, and in 1267 many coastal towns are formally incorporated with the Venetian state.