Under him Avicenna read the Isagoge of Porphyry and the first propositions of Euclid.
At the age of twenty-two Avicenna lost his father.
Avicenna seems to have declined the offers of Mahmud the Ghaznevid, and proceeded westwards to Urjensh in the modern Khiva, where the vizier, regarded as a friend of scholars, gave him a small monthly stipend.
Avicenna himself was at this season stricken down by a severe illness.
Finally, at Jorjan, near the Caspian, he met with a friend, who bought near his own house a dwelling in which Avicenna lectured on logic and astronomy.