It occupied the northwest part of the island from the 11th through the 13th century, bordering the Gallura to the east, Arborea to the south, and Cagliari to the southeast.

Sardinia was an imperial province of the Byzantine Empire until the 9th century, when the Arabs and Imazighen began pursuing aggressive policies of expansion and piracy in the Mediterranean.

The conquest of Sicily by these groups in 827 effectively cut Sardinia off from the central government and military might of the empire, and the Byzantines found the island increasingly difficult to supply and defend.

In the absence of instruction or reinforcement, the Sardinian provincial Byzantine officials, called iudici ("judges") began to govern autonomously.

By 1073, these districts had become de facto independent states, their ruling kings still titled as iudices or judikes ("judges"') after their imperial civil servant predecessors.