What were the four self-governing giudicati of medieval Sardinia?

During the 11th century, medieval Sardinia was organized into four distinct, self-governing divisions known as giudicati. These territories were governed by lifelong rulers called giudici ("judges") and eventually evolved into hereditary principalities.1

The four giudicati were:

• Cagliari1
• Arborea1
• Torres1
• Gallura1

These divisions became central to the political and economic influence of the Italian maritime republics of Pisa and Genoa, which sought to secure zones of control across the island through alliances with the giudici.1