Free Non-Muslims in Egypt during the First Fatimid Period Agriculture in Khaybar in Pre-Islamic Times and until Omar Ibn El-Khatab’s Caliphate. Trade in Khaybar in Pre-Islamic Times and until Omar Ibn El-Khatab’s Caliphate. Arab Tribes in Qalyubia in Islamic Period. The Political Role of the Bani Shaiba the Custodians of the Holly Kaaba. Villages and Cities of Qalyubia from the Islamic Conquest until the End of Mamluk Period.