His later works embody his pessimistic, sceptical philosophy of life and his rational approach to its problems. In one epistle he peopled limbo with reputed heretics and free- thinkers enjoying themselves and discussing textual criticism. It was this treatise that had a stimulative effect on Dante's Divine Comedy. In another book he tried to imitate the Koran, a sacrilege in Moslem eyes. The philosophy ad- vocated in this work is basically Epicurean. Al-Maarri was one of the few Arabic poets who rose above limitations of time and place to the realm of universal humanity.
Though the Fatimids had had difficulty in maintaining their precarious hold on Syria, first against Turks and Carmathians, then against Hamdanids and Byzantines, and later against Mirdasids and other bedouin assailants, their most formidable adversary did not appear on Syrian territory until 1070, by which time Fatimid rule had virtually col- lapsed because of rebellion in Egypt (1060). Sunnite Turkish Seljuks had pushed south from Turkestan to the region of Bukhara, embraced Islam there and continued their victorious drive until in 1055 their leader Tughril had forced the powerless Abbasid caliph to accept him as master instead of the Shiite Persian Buwayhids. Tughril assumed the title sultan, becoming the first Moslem ruler whose coins bear this title.
Under TughriPs nephew and successor Alp Arslan (1063- 1072), the Seljuk empire was extended westward into Syria and Asia Minor. In 1070 Alp advanced against the Mirdasids in northern Syria and occupied Aleppo, leaving the Mirdasid governor as his vassal. The Turkoman general Atsiz pushed into Palestine and captured al-Ramlah, Jerusalem and other towns as far south as Ascalon, whose Fatimid garrison held out. In the following year Alp won a decisive victory over the Byzantines at Manzikert, north of Lake Van, and took the emperor himself prisoner. All Asia Minor then lay open to the Turks. Hordes of them rushed into Anatolia and northern Syria. Turkish generals penetrated as far as
