The next great philosopher was _Muhammad b. Muhammad b. Tarkhan Abu Nasr al-Farabi_ (d. 339), of Turkish descent. He was “a celebrated philosopher, the greatest indeed that the Muslims ever had; he composed a number of works on logic, music, and other sciences. No Musulman ever reached in the philosophical sciences the same rank as he, and it was by the study of his writings and the imitation of his style that Avicenna attained proficiency and rendered his own works so useful.” (Ibn Khallikan, iii. 307). He was born at Farab or Otrar near Balasaghum, but travelled widely. In the course of his wanderings he came to Baghdad but, as at the time he knew no Arabic, he was unable to enter into the intellectual life of the city. He set himself first to acquire a knowledge of the Arabic language, and then became a pupil of the Christian physician Matta b. Yunus, who was at that time a very old man, and under him he studied logic. To increase his studies he removed to Harran, where he met the Christian philosopher Yuhanna b. Khailan, and continued to work at logic under his direction. He then returned to Baghdad, where he set to work at the Aristotelian philosophy, in the course of his studies reading the _de anima_ 200 times, the _Physics_ 40 times. His chief interest, however, was in logic, and it is on his logical work that his fame chiefly rests. From Baghdad he went to Damascus, and thence to Egypt, but returned to Damascus, where he settled for the rest of his life. At that time the empire of the Khalifa of Baghdad was beginning to split up into many states, just like the Roman Empire under the later Karlings, and the officials of the Khalifate were forming semi-independent principalities under the nominal suzerainty of the Khalif and establishing hereditary dynasties. The Hamdanids Shi`ites, who began to rule in Mosul in 293, established themselves at Aleppo in 333 and achieved great fame and power as successful leaders against the Byzantine emperors. In 334 (= 946 A.D.) the Hamdanid Prince Sayf ad-Dawla took Damascus, and al-Farabi lived under his protection. At that period the orthodox were distinctly reactionary, and it was the various Shi`ite rulers who showed themselves the patrons of science and philosophy.