During Byzantine Empire from 327 AC until 1346 AC, Mesta was evolved to its final form with the around scattered settlements to be united into one. The village was constructed as a fort in order to offer protection from the Arab pirate raids. The most destructive raids took place between the years 688 and 678 AC under the reign of Emperor Constantine the Pogonatos. From 1124 AC until 1173 AC the island of Chios was occupied by the Venetians. After this period Chios and Mesta returned to the Byzantine domination. In 1204 AC when Byzantium was seized by the West, Chios entered under the rule of the Latin Emperor of Constantinople. It was the second time in a century that Mesta was conquered by the Latins. When the Byzantines recaptured Chios the raids continued with the most important one to be the Catalans raid in 1303 AC.
This raid is considered of great importance because all the mastic trees were destroyed and took many years for the production to recover. In 1304 AC and for a period of ten years Chios had been granted to the Genoese by the Byzantine Emperor in order to avoid the occupation of the islands by the Turks. The Genoese didn’t abide by the agreement and occupied Chios until 1329 AC when the Byzantine Emperor Andronicus seized it again.