The Guilcer (or Guilcier) derives its name from the ancient post-judicial department called Part Cier Real with its headquarters Guilarze (today Ghilarza). After the Battle of Macomer of 1477, during which the Catalan-Aragonese defeated definitively the army of the Judge of Arborea, the district of Guilceri came
Divided into parts of the Cier Canales (comprising the territories of the Middle Tirso, Sedilo, Domas Novas Canales and Norbello valleys), and Part Cier Real (comprising the territories of Ghilarza, Abbasanta, Paulilatino, the rest of Norbello, Aidomaggiore). Part Cier Canales was assigned to the Sedilo feudal, while Part Cier Real was directly infested with the Aragonese Crown. The countries of Seneghe, Narbolia, Bonarcado and Milis, stayed at the Marchesato of Oristano under the name of Part Milis. Following the judgment of the felony against the Marchesato of Oristano, on August 12, 1479, King Ferdinand II of Aragon withdrew the area to the Marquis, bringing it indissolubly to the Crown, and giving at the same time the faculties of the inhabitants to withstand even with weapons to Any attempt to modify a state without incurring any punishment. The King then granted the Guil-Cier countries the right to teach with a banner. The feudal rights that these villages owed to the Crown consisted of feudal rights (paid money), grain and barley rights, wine rights, tithes of the cattle (degumarum), straw rights and Alcadia, who were paid for Tanca Regia Administrators The Spanish Crown excluded this territory from being defeated with the aim of ensuring the maintenance of the horse breed of Tanca Regia (a farm already existing in the late Roman Empire, continued in the Byzantine era, and Resumed by the Judges of Arborea). Tax accounting remained distinct for Guilarze and the rest of Part Cier Real until 1490 when Isabella of Castile, urged to fund Cristoforo Colombo’s adventure, ordered his tax collectors a tax deduction supplement.
The ancient territory of Barigadu occupies the area south of Lake Omodeo. Its landscape is characterized by the presence of Mediterranean scrub and cork, which grow lush due to favorable weather conditions. In the Natural Landscape Oasis of Assai, among the Neoneli and Nughedu Santa Vittoria, it is possible to observe closely animal species such as Sardinian deer, deer, wild boar and various species of wild birds. Near the towns of Busachi and Allai, which still preserve the ancient rural buildings, there is a Roman bridge that leads to Fordongianus, the ancient city called Forum Traiani, where there are the ancient ruins of Roman baths. Omodeo Lake, the dynamic center of the area, is man’s work. The first artificial basin was made with the construction of the Santa Chiara Dam near Ulà Tirso. It was completed in 1924, resulting in what was at the time the largest artificial lake in Europe, given its maximum capacity of 403 million cubic meters of water. Work on its construction was part of a wider project, including the reclamation of the Oristano plain, and envisaged the use of 16,000 workers. The project was drafted by engineer Angelo Omodeo, who also participated in the construction of the large dams on the Nile. The construction was completed in five years, under the direction of engineer Giulio Dolcetta. With its more than 22 km / h, the basin was built to regulate river floods, produce electricity and provide water for irrigation of the Campidano plain.