umayyad islam conquest conquests 8th centuries expansion islami islamische ausbreitung levik mittelalter invasion omeyyades christentum
abbasid caliphate umayyad islamic dynasty 9th ummayad britannica 1450 decline caliphs califfato guided
umayyad under expansion caliphate abbasid rashidun islam muhammad map islamic history caliphates rule spread modern arab empires world day spain