 Under Byzantine rule , Haifa continued to grow but did not assume major importance . Following the Arab conquest of Palestine in the <unk> @-@ 40s , Haifa was largely overlooked in favor of the port city of ' Akka . Under the <unk> Caliphate , Haifa began to develop . In the 9th century under the <unk> and <unk> <unk> , 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 were the city 's most lucrative industries . 
