Between 824 and 827, Andalusian Muslim exiles who had previously seized and settled in Alexandria in Egypt gradually conquered Crete. They were led by Abu Hafs Umar, known in Byzantine sources as Apohapsis. On the island they established a largely autonomous Muslim state, known as the Emirate of Crete, which survived until the Byzantine reconquest of 961.

The new rulers founded and fortified the city of Chandax on the northern coast, on the site of modern Heraklion. Its name derived from the Arabic word al-khandaq, meaning ditch or trench, after the large defensive moat surrounding its fortifications. Chandax developed into the capital of the emirate, an important commercial port and a powerful naval base in the eastern Mediterranean.

Raids were launched from Crete against Byzantine islands, ships and coastal regions. Maritime trade, piracy and the trafficking of captives, many of whom were sold into slavery, became important sources of wealth for the emirate. At the same time, the island’s strategic position along the maritime routes of the Mediterranean strengthened its commercial connections with Egypt, North Africa and the wider Islamic world.

The loss of Crete created a serious strategic problem for the Byzantine Empire, as the island was used as a base for raids across the Aegean. The Byzantines organised repeated campaigns to recover it, but most ended in failure. One of the largest unsuccessful expeditions took place in 949.

In 960, a major new campaign was launched under the command of General Nikephoros Phokas, who later became Byzantine emperor. The Byzantine army landed on Crete and besieged Chandax for several months. The city was captured in March 961, bringing the Emirate of Crete to an end and restoring the island to the Byzantine Empire.