Under Byzantine rule , Haifa continued to grow but did not assume major importance . Following the Arab conquest of Palestine in the 630s @-@ 40s , Haifa was largely overlooked in favor of the port city of ' Akka . Under the Rashidun Caliphate , Haifa began to develop . In the 9th century under the Umayyad and Abbasid Caliphates , Haifa established trading relations with Egyptian ports and the city featured several shipyards . The inhabitants , Arabs and Jews , engaged in trade and maritime commerce . Glass production and dye @-@ making from marine snails was the city 's most lucrative industries .