Arborea was a small kingdom in the later Middle Ages, one of the four "judicatures" (Gallura, Logudoro, Arborea, and Caralisinto) which the island was divided. Its rulers used the title "Judge". The most famous of these local princes was lady Eleanor of Arborea, after whose death (1404) soon Arborea lost its independence to the Kingdom of Aragon.

Eleanor was regent on behalf of her sons, in turn: Federico I and Mariano V. Eleanor died in 1404, Mariano V in 1407, after which the succession descended to William of Narbonne of Arborea, Viscount of Narbonne, grandson of Beatrice. Martin's sudden death made possible a recovery and occupation of Sassari and part of Logoduro, as well as reclamation of the title of Judge of Arborea by William.

In 1420 Alfonso V of Aragon purchased the rights of the viscounts of Narbonne. Other giudicatos fell sooner or later, and the last, the giudicato of Arborea successfully resisted Aragonese for the longest time, and for a time (during Eleanor) came to control nearly the entire island, but its last ruler (viscount of Narbonne) was eventually defeated by the Aragonese (lead by Martin the Younger, Lord of Sicily) in the decisive Battle of Sanluri, 30 June 1409.