By the time Constantine accepted Christianity for himself, the new religion was probably already predominant on Cyprus, owing basically to the early missionary work of Paul, Barnabas, and Mark. Earthquakes in the early fourth century created havoc on the island, and drought seriously damaged the economy. However, the most significant event of the century was the struggle of the Church of Cyprus to maintain its independence from the patriarchs of Antioch. Three bishops represented Cyprus at the first Ecumenical Council of Nicaea in 325. At the second council (Sardica, 343), there were twelve Cypriot bishops, indicating a great increase in the number of communicants in the intervening years.

A major struggle concerning the status of the Church of Cyprus occurred at the third council, at Ephesus, in 431. The powerful patriarch of Antioch argued forcefully that the small Cypriot church belonged in his jurisdiction, but the Cypriot bishops held their ground, and the council decided in their favor. Antioch still did not relinquish its claim, however, and it was not until after the discovery of the tomb of Saint Barnabas containing a copy of the Gospel of St. Matthew allegedly placed there by the apostle Mark that Emperor Zeno intervened and settled the issue. The Church of Cyprus was confirmed as being auto cephalous, that is, ecclesiastically autonomous, enjoying the privilege of electing and consecrating its own bishops and archbishops and ranking equally with the churches of Antioch, Jerusalem, Alexandria, and Constantinople.

Except for the religious disputes, a period of calm prevailed on Cyprus during the early Byzantine centuries. The social structure was rigid and codified in law. Under a law issued by Constantine, tenant farmers were made serfs and forbidden to leave the land on which they were born. A later law allowed runaways to be returned in chains and punished. Administration was highly centralized, with government officials responsible directly to the emperor. The wealthy landlord and merchant classes retained their age-old privileges. The connection between church and state grew closer. The pervasive organization and authority of the church, however, sometimes benefited the common man by interceding in cases of abuse of power by public officials or wealthy persons. During the fifth and sixth centuries, the level of prosperity permitted the construction of major cathedrals in several of the island's cities and towns. Salamis, renamed Constantia, again became the capital and witnessed another era of greatness. Archaeologists have uncovered an enormous fourth century basilica at the site.

The peace that many generations of Cypriots enjoyed during the middle centuries of the first millennium A.D. was shattered by Arab attacks during the reign of Byzantine emperor Constans II (641-68). Sometime between 647 and 649, Muawiyah, the amir of Syria (later caliph of the Muslim empire), led a 1,700-ship invasion fleet against Cyprus. Constantia was sacked and most of its population massacred. Muawiyah's destructive raid was only the first of a long series of attacks over the next 300 1000 0 years. Many were merely quick piratical raids, but others were large-scale attacks in which many Cypriots were slaughtered and great wealth carried off or destroyed. No Byzantine churches survived the Muslim attacks. In A.D. 965, General Nicephorus Phocas (later emperor), leading the Byzantine imperial forces, drove the Arabs out of Crete and Cilicia and scored a series of victories on land and sea that led to the liberation of Cyprus after more than three centuries of constant turmoil.

The pitiable condition of the Cypriots during the three centuries of the Arab wars can only be imagined. Thousands upon thousands were killed, and other thousands were carried off into slavery. Death and destruction, rape and rampage were the heritage of unnumbered generations. Many cities and towns were destroyed, never to be rebuilt.

In the twelfth century Isaac Comnenos, a Byzantine governor, set himself up in the capital as the emperor of Cyprus, and the authorities in Constantinople were either too weak or too busy to do anything about the usurper. When an imperial fleet was eventually sent against Cyprus, Comnenos was prepared and, in league with Sicilian pirates, defeated the fleet and retained control of the island. Comnenos, a tyrant and murderer, was unlamented when swept from power by the king of England, Richard I the Lion-Heart.

After wintering in Sicily, Richard set sail en route to the Holy Land as a leader of the Third Crusade. But in April 1191 his fleet was scattered by storms off Cyprus. Two ships were wrecked off the southern coast, and a third, carrying Richard's fiancée Berengaria of Navarre, sought shelter in Lemesos (Limassol). The wrecked ships were plundered and the survivors robbed by the forces of Comnenos, and the party of the bride-to-be was prevented from obtaining provisions and fresh water. When Richard arrived and learned of these affronts, he took time out from crusading, first to marry Berengaria in the chapel of the fortress at Lemesos and then to capture Cyprus and depose Comnenos. The capture of Cyprus, seemingly a footnote to history, actually proved beneficial to the crusaders whose foothold in the Holy Land had almost been eliminated by the Muslim commander Saladin. Cyprus became a strategically important logistic base and was used as such for the next 100 years.

When Richard defeated Comnenos, he extracted a huge bounty from the Cypriots. He then appointed officials to administer Cyprus, left a small garrison to enforce his rule, and sailed on to the Holy Land. A short time later, the Cypriots revolted against their new overlords. Although the revolt was quickly put down, Richard decided that the island was too much of a burden, so he sold it to the Knights Templars, a Frankish military order whose grand master was a member of Richard's coterie. Their oppressive, tyrannical rule made that of the avaricious Comnenos seem mild in comparison. The people again rebelled and suffered a massacre, but their persistence led the Templars, convinced that they would have no peace on Cyprus, to depart. Control of the island was turned over to Guy de Lusignan, the controversial ruler of the Latin (see Glossary) kingdom of Jerusalem, who evidently agreed to pay Richard the amount still owed him by the Templars. More than 800 years of Byzantine rule ended as the Frankish Lusignan dynasty established a Western feudal system on Cyprus.

Data as of January 1991