Of the period 200 until 700 A.D. very little is known of the fate of the island. Assumed is that Chios was victim of pirates pillaging. Not until the Byzantine empire came in control of Crete the life started the improve on Chios. In the 11th century the Byzantine emperor Monomachus founded the monastery of Nea Moni. This was the result of the emperors promise to an Christian Saint who foresaw his rule. During this period the island was protected from the Turks by the Byzantine empire.
The Island was handovered to the Genoese in the year 1200 A.D. It was in special interest of the Venetians as Chios was on a trade route with the black sea. The island was between 1329 and 1349 under Byzantine rule due to a trade dispute between the Genoese and the Byzantine empire. After 1349 Chios was controlled by the Genoese firm Maona.
Under the new Genoese rule the island flourished again, until the extend that Chios was now known as the "paradise of the east". The standard of living was high due to the use of natural resources of the island such as the agriculture , silk worms and mastic. The Genoese kept Chios out of the hands of the Turks even after the fall of Constantinople. As a guest of the Genoese family Christopher Columbus visited Chios before his voyage to the west. There are historians who believe that Christopher Columbus obtained naval charts to support his voyage to the west.