The Byzantine age in Sardinian history conventionally begins with the island's reconquest by Justinian I in 534. This ended the Vandal dominion of the island after about 80 years. There was still a substantial continuity with the Roman phase at this time.
History Origin Sardinia was reconquered by the Byzantine empire during the Vandalic War for possession of Africa. Having defeated the Vandals in Africa at the Battle of Tricamarum, and having victory in hand, the Byzantine general Belisarius sent general Cyril to Sardinia with a fleet to subdue it.
[Belisario] immediately sent Cyril with the chief of Zazone and many soldiers to Sardinia, since the islanders, fearful of the Vandals and still not sure of what had happened near Tricamaro [the Vandal defeat], refused to obey. to Justinian. ... Cyril then landed in Sardinia, and exposed Zazone's head in a public place, honorably managed to reduce the two islands [Sardinia and Corsica] tributaries of the empire as they once were.Procopio, De Bello Gothico, IV,22.
Emperor Justinian established that Sardinia were constituted as a ducatus (duchy) within the Exarchate of Africa.
From this [prefecture], with the help of God, seven provinces with their judges will depend, of which Zeugi, which was previously called Proconsular Carthage, Byzacium and Tripoli will have consulares as governors; while the others, namely Numidia, Mauritania and Sardinia will be, with the help of God, governed by praesides".Justinian Code, I.XXVII
Despite the new establishment, the Byzantines could not pacify the Barbaricini, who had control of the interior of the isle. So, in the decade of 530, the magister militum per Africam Solomon sent some duces to Sardinia to fight against them.Procopio, De Bello Vandalico, II,13. The dux of Sardinia, who had the task of fighting against the Barbaricini, had his residence in the mountains of Barbagia, where this people lived, reluctant to allow themselves to be subjugated.Cod. Iust. de off. praef. Africae I 27, 2, 3: In Sardinia autem iubemus ducem ordinari et eum iuxta montes, ubi Barbaricini videntur sedere, habentem milites pro custodia locorum quantos et ubi tua magnitudo providerit. Precisely the dux's seat was the Forum Traiani, the walls of which were rebuilt at the behest of Justinian.Procopio, De aedificiis, VI,7.
Barbarian Invasions In the year 551, the Ostrogothic king Totila invaded the island and occupied it.Ortu, Gian Giacomo (2005) La Sardegna dei Giudici p.21-22 The magister militum per Africam, John Troglita attempted to recover it, but was defeated by the Goths
Now, Totila desired to seize the islands belonging to Libya. He therefore immediately assembled a fleet of ships, and, putting on board a suitable army, sent it to Corsica and Sardinia. This fleet first sailed towards Corsica and, finding no defenders, took the island and then also took possession of Sardinia. And Totila subjected both islands to paying tribute. But when John, who commanded the Roman army in Libya, heard about this, he sent a fleet of ships and a strong army of soldiers to Sardinia. And when they were near the city of Caralis, they camped to lay siege; but they did not believe themselves capable of assaulting the walls, since the Goths had a sufficient garrison there. When the barbarians heard of this, they made a sortie against them from the city and, suddenly falling upon their enemies, defeated them without difficulty and killed many of them.Procopio di Cesarea, De Bello Gothico
However, after the defeat of Totila and Teia (552) and the submission of the Goths, Sardinia was recovered by the Empire.
The invasion of the Italian Peninsula by the Longobards in 568, which changed the face of Italy, only resulted in a few coastal raids on Sardinia, even if there are traces of their presence on the island, documented by the discovery of various objects, including numerous coins. A failed Longobard invasion affected Cagliari in 599, but it was repelled.
Time of Pope Gregory I During the pontificate of Pope Gregory I (590-604), Sardinia was included within the Roman sphere, participating in the work of protection, administration and evangelization of this pontiff. He wrote numerous letters dedicated to Sardinian dignitaries. Those letters are the richest documentation preserved about this time. They shown the continued division of Sardinia into a Romanized zone (coasts and coastal cities, plain) and a still barbaric internal region, Barbagia. Pope Gregory I worked to convert these inland populations to Christianity by sending letters and emissaries. In particular, he sent Dux Zabarda who in 594 stipulated a pact with the leader of the Barbaricini named Hospito.
In 595, Gregory sent a bishop to Sardinia to continue the mission of conversion. It was discovered that the Iudex Provinciae of Sardinia, in order to recover the money lost to purchase the governorship, was allowing pagans to continue worshiping their idols in exchange for paying a tax:Pope Gregorio I, Epistolae, V,41.
Learning that many of the natives of Sardinia still... make sacrifices to idols..., I sent one of the bishops of Italy, who... converted many of the natives. But he told me that... those who sacrifice idols on the island pay a tax to the governor of the province for doing so. And, when some were baptized and stopped making sacrifices to idols, the said governor of the island continued to demand payment of the tax... And, when said bishop spoke with him, he responded that he had promised him a suffrage. so great that I would not have been able to pay it if I had not acted in this way... I suspect that such misdeeds have not reached your most pious ears, because if they had, they would not have continued to this point. day at all. But it is time for Our Most Pious Lord [the Emperor] to find out about this, so that he can remove such a serious burden of guilt from his soul, from the Empire and from his children. I know that you will say that what is withdrawn from these islands is used in the expenses of the armies for their defense; but perhaps this is the reason for the little benefit they obtain from such collections, since they are taken from others and not without an admixture of guilt.Pope Gregorio I, Epistole, V,41.
7th Century A Theodorus is mentioned as the praeses eiusdem Sardiniae in a letter of Pope Honorius I dated June 10, 627, in which Honorius describes Theodorus preventing the clergy of Cagliari from sailing to Rome on Honorius' summons and instead redirecting them to Africa, and asks the praetorian prefect of Africa Gregorius to punish Theodorus and send the clergy to Rome as requested.
Muslim raids In 806-807, the Moors from Spain attempted an incursion in Sardinia, which were blocked and the invasors suffered serious losses. According to the chronicler Einhard, 3,000 men fell in battle.Einhard, Annales regni Francorum inde ab a. 741 usque ad a. 829, qui dicuntur Annales Laurissenses maiores et Einhard, pg.124.
In 810, Sardinia and Corsica were attacked by Moors from all Spain (Mauri de tota Hispania), en route for Corsica, which they took as it was undefended. Two years later a fleet coming from Africa and Spain to ravage Italy split into two parts, and the part which was brought to Sardinia was nearly wiped out.
Moorish pirates also established some bases in Sardinia. They used Tavolara Island as base for a major attack on Rome in 845.L.M. Duchesne, ed, Liber Pontificalis, vol. 2, 2 vols, pg.117.
Archontate After the fall of Carthage to the Arabs, Sardinia was an autonomous archontate of the Byzantine Empire ruled by a Judex or Judge. The Archonate lasted until its fragmentation during the first half of the eleventh century, when it was replaced by two Sardinian medieval kingdoms – the Judicates of Torres and Cagliari. The Judicate of Cagliari had institutional continuity with the Archontate era, having a locally elected Judge who reported back to Constantinople as an Archon between 533 and 1015, and acted as an independent administrator between 1015 and 1258. In 1073, when the records improved, four kingdoms are recorded (Torres, Calari, Gallura and Arborea).
In 815, ambassadors from Sardinia went to the Carolingian Empire, with gifts to Emperor Louis the Pious, possibly to request military assistance against the Arab attacks.Einhard, Annales regni Francorum inde ab a. 741 usque ad a. 829, qui dicuntur Annales Laurissenses maiores et Einhard, pg.143. Later, in 829, the Count Bonifacio (Carolingian feudal lord in charge of defense of Corsica) arrived in Sardinia, searching for help from Sardinian authorities for his counterattack of the Arab pirates in the African coasts.
From the mid-9th century, the popes interacted with the supreme ruler in Sardinia called the ('judge'). So it was the letter of Pope Leo IV (847– 55) to the of Sardinia: "[...] to the of Sardinia. We have thought to beg your highness to deign to send us, as many as your magnificence sees fit, Sardinians, adults or young men with their weapons, who might be able to carry out for us every day orders."Hirsch- Gereuth, editor, Epistolae selectae Sergii II., Leonis IV., Benedicti III., pontificum Romanorum’ in Epistolae Karolini Aevi iii, mgh Epp. 5 (Berlin, 1899), no. 17 p. 596
Later pontifical letters until the eleventh century would show the gradual reduction of the institutional and political importance of the in the eyes of the popes. Byzantium ceased to send military officials to Sardinia after the middle of the ninth century. It is possible that, after the start of the Aghlabid conquest of Sicily in 827, the Byzantine army was regionalised, and that some noble family of Sardinia had assumed the title of , in accordance with the provisions of Justinian I, and also claimed the military power of the . From the pontifical letters of Pope Nicholas I (858–67) and John VIII to Sardinia, it isn't clear if the island was divided at this point or a central authority remained in the island, but an increasing consensus saw that a supreme ruler of Sardinia (the ) had supremacy over local as local .Spanu et al., L’arcontato d’Arborea tra Islam ed eredità bizantina, pg 525
The Byzantium Emperor Constantine VII named the ruler of Sardinia (a nominal and autonomous vassal at this time) as in his book De Cerimoniis (956–959 AD). He also mentioned the existence of Sardinian imperial guards:
To the archon of Sardinia, a two-solidi gold seal. Mandate from the Christ-loving ruler to the archon of Sardinia. To the duke of Venice; to the prince of Capua; to the prince of Salerno; to the duke of Naples; to the archon of Amalfi; to the archon of Gaeta.J.J. Reiske, ed.,Constantini Porphyrogeniti imperatoris De cerimoniis aulae Byzantinae libri duo, 2nd ed., vol. 1, 2 vols, Corpus Scriptorum Historiae Byzantinae (Bonn, 1829), chapter 48 pg 690.
The archontate is also attested in local inscriptions in churches from the end of the tenth century (naming some archons as Torchotorio and Salousio)A. Guillou, Recueil des inscriptions grecques médiévales d’Italie, Collection de l’École française de Rome 222, no. 215 pg. 235. and some seals from the period.
Lord, help the servants of God and our most noble archontes Torchoutorio, imperial (proto) spatharios, and Salousio our most noble archontes. Amen. Remember, Lord, also your servant Ortzokor. Amen.A. Guillou, Recueil des inscriptions grecques médiévales d’Italie, Collection de l’École française de Rome 222, no. 215 pg. 239-240..