Sykes' History of Persia Vol 2 (pdf) - Heritage Institute

THE EARLY ABBAS1D PERIOD 67
incidents made familiar to English readers in Moore's
well-known poem. Its hero, Mokanna, known as Hakim
Burkai, or " the Physician with the face-veil," was born
at Karez, which is now a squalid village on the road
between Meshed and Herat. He taught the immanence
of the Deity in Adam, in Abu Muslim, whose name was
still intensely revered, and in himself. 1 For four years
he held Central Asia, until, being besieged and seeing no
hope, he cast himself into a tank of vitriol.
Hadi, A.H. 169-170 (785-786). Mehdi's favourite
son was Haroun, who had gained much glory
in a campaign
to the Bosphorus
in A.H. 156, and he wished to pass over
his elder son Musa, better known as Hadi ;
but the
latter refused to renounce his rights,
and on the sudden
death of Mansur he was proclaimed Caliph without
opposition. His reign, however, was short and unimportant,
and when he died, after ruling for about a
year, he was succeeded by his brother, who has achieved
enduring fame as Haroun-al-Rashid, or " Aaron the
Upright." Under him the golden age of Islam was
ushered in.
1
Browne points out the essential identity of all these sects and gives details in vol. i.
ix. of his work.