In 238 BC, Sardinia became, along with Corsica, a
joint province of the
Roman Republic. The Romans ruled the island until the middle of the 5th century when it was occupied by the
Vandals, who had also
settled in north Africa. In 534 AD it was
reconquered by the
Eastern Roman (Byzantine) Empire. It remained a Byzantine province until the
Muslim conquest of Sicily in the 9th century. After that, communications with the Byzantine capital,
Constantinople, became very difficult, and powerful families of the island assumed control of the land. Starting from 705 to 706,
Saracens from north Africa (
recently conquered by Arab armies) harassed the population of the coastal cities. Facing Arab attempts to sack and conquer the island, while having almost no outside help, Sardinia used the principle of
translatio imperii ("transfer of rule") and continued to organize itself along the ancient Roman and Byzantine model. The island was not the personal property of the ruler and of his family, as was then the dominant practice in western Europe, but rather a separate entity and during the Byzantine rule, a
monarchical republic, as it had been since Roman times. Information about the Sardinian political situation in the following centuries is scarce. Due to Saracen attacks, in the 9th century
Tharros was abandoned in favor of
Oristano, after more than 1800 years of occupation;
Caralis,
Porto Torres, and numerous other coastal centres suffered the same fate. There is a record of another massive Saracen sea attack in 1015–16 from the
Balearics, commanded by
Mujāhid al-ʿĀmirī (Latinized as
Museto). The Saracen attempt to invade the island was stopped by the
Judicates with the support of the fleets of the
maritime republics of
Pisa and
Genoa. Pope
Benedict VIII also requested aid from the two maritime republics in the struggle against the Arabs. After the
East–West Schism, Rome made many efforts to restore
Latinity to the Sardinian church, politics and society, and to finally reunify the island under one Catholic ruler, as it had been for all of southern Italy, when the Byzantines had been driven away by Catholic
Normans. Even the title of "Judge" was a Byzantine reminder of the Greek church and state, in times of harsh relations between eastern and western churches (
Massacre of the Latins, 1182,
Siege of Constantinople (1204),
Recapture of Constantinople, 1261). Before the Kingdom of Sardinia and Corsica, the
archons (), or in Latin, who reigned in the island from the 9th or 10th century until the beginning of the 11th century, can be considered real kings of all Sardinia (), even though nominal vassals of the Byzantine emperors. Of these sovereigns, only two names are known: Turcoturiu and Salusiu ( (), who probably ruled in the 10th century. The archons still wrote in Greek or Latin, but one of the oldest documents left of the
Judicate of Cagliari (the
Carta Volgare), issued by
Torchitorio I de Lacon-Gunale in 1070, was already written in the
Romance Sardinian language, albeit with the
Greek alphabet. The realm was divided into four small kingdoms, the Judicates of
Cagliari,
Arborea,
Gallura and
Logudoro, perfectly organized as was the previous realm, but was now under the influence of the
papacy, which claimed sovereignty over the entire island, and in particular of the
Italian states of Genoa and Pisa, that through alliances with the "judges" (the local rulers), secured their political and economic zones of influence. While Genoa was mostly, but not always, in the north and west regions of Sardinia, that is, in the Judicates of Gallura and Logudoro; Pisa was mostly, but not always, in the south and east, in the Judicates of Cagliari and Arborea. That was the cause of conflicts leading to a long war between the Judges, who regarded themselves as kings fighting against rebellious nobles. Later, the title of King of Sardinia was granted by the Emperor of the Holy Roman Empire to
Barisone II of Arborea, and subsequently also to
Enzio of Sardinia. The first could not reunify the island under his rule, despite years of war against the other Sardinian judges, and he finally concluded a peace treaty with them in 1172. The second did not have the opportunity. Invested with the title from his father,
Emperor Frederick II in 1239, he was soon recalled by his parent and appointed Imperial Vicar for Italy. He died in 1272 without direct recognized heirs after a detention of 23 years in a prison in Bologna. The Kingdom of Sardinia and Corsica, later only the Kingdom of Sardinia from 1460, was a state whose king was the
King of Aragon, who started to conquer it in 1324, gained full control in 1410, and directly ruled it until 1460. In that year it was incorporated into a sort of confederation of states, each with its own institutions, called the
Crown of Aragon, and united only in the person of the king. The Crown of Aragon was made by a council of representatives of the various states and grew in importance for the main purpose of separating the legacy of
Ferdinand II of Aragon from that of
Isabella I of Castile when they married in 1469. The idea of the kingdom was created in 1297 by
Pope Boniface VIII, as a hypothetical entity created for
James II of Aragon under a secret clause in the
Treaty of Anagni. This was an inducement to join in the effort to restore
Sicily, then under the rule of James's brother
Frederick III of Sicily, to the
Angevin dynasty over the oppositions of the Sicilians. The two islands proposed for this new kingdom were occupied by other states and fiefs at the time. In Sardinia, three of the four states that had succeeded
Byzantine imperial rule in the 9th century had passed through marriage and partition under the direct or indirect control of Pisa and Genoa in the 40 years preceding the
Treaty of Anagni. Genoa had also ruled
Corsica since conquering the island nearly two centuries before (c. 1133). There were other reasons beside this papal decision: it was the final successful result of the long fight against the
Ghibelline (pro-imperial) city of Pisa and the Holy Roman Empire itself. Furthermore, Sardinia was then under the control of the very Catholic kings of Aragon, and the last result of rapprochement of the island to Rome. The Sardinian church had never been under the control of the
Ecumenical Patriarchate of Constantinople; it was an autonomous province loyal to Rome and belonging to the
Latin Church, but during the Byzantine period became influenced by Byzantine liturgy and culture. == Foundation of the Kingdom of Sardinia ==