Early Islamic era
In the 7th century CE a town named "Kolzum" stood just north of the site of present-day Suez and served as eastern terminus of a canal built by Amr ibn al-'As linking the Nile River and the Red Sea. Kolzum's trade fell following the closure of the canal in 770 by the second Abbasid caliph al-Mansur to prevent his enemies in Arabia from accessing supplies from Egypt and the lands north of it. Nonetheless, the town benefited from the trade that remained between Egypt and Arabia. By 780 al-Mansur's successor al-Mahdi restored part of the canal. The Qarmatians led by Hasan ibn Ahmad defeated a Fatimid army headed by Gawhar al-Siqilli at Kolzum in 971 and thereby captured the town. Following his defeat in Cairo by al-Siqilli at the end of that year, Hasan and his forces retreated to Arabia via Kolzum. Suez was situated nearby and served as a source of drinking water for Kolzum according to Arab traveler al-Muqaddasi who visited in 986.
The Ayyubid sultan of Egypt, Saladin, fortified both Kolzum and Suez in to defend Egypt's eastern frontier from Crusader raids by Raynald of Chatillon. Between 1183-84, Raynald had ships stationed in the Red Sea to prevent the Ayyubid garrison at Kolzum from accessing water. In response, Saladin's brother al-Adil had Husam ad-Din Lu'lu build a naval fleet which sailed to the southern port of Aidab to end Raynald's venture. By the 13th century it was recorded that Kolzum was in ruins as was Suez which had gradually replaced the former as a population center. According to Muslim historians al-Maqrizi and al-Idrisi, Kolzum had once been a prosperous town, until it was occupied and plundered by Bedouins. Arab geographer al-Dimashqi noted that Kolzum belonged to the Mamluk province of al-Karak at the time.
Ottoman and Egyptian rule
To prevent Portuguese attacks against Egyptian coastal towns and the Red Sea port of Jeddah, Qansuh al-Ghawri the last Mamluk sultan ordered a 6,000-man