He is to be distinguished from another Alhazen who translated Ptolemy's Almagest in the 10th century.
The first Arabic translation of the Almagest was made by order of Harun al-Rashid about the year Boo; others followed, and the Caliph Arah al-Mamun built in 829 a grand observatory at astro- Bagdad.
He lectured with applause at Vienna from 1450; was joined there in 1452 by Regiomontanus; and was on the point of starting for Rome to inspect a manuscript of the Almagest when he died suddenly at the age of thirty-eight.
A quarrel with George of Trebizond, the blunders in whose translation of the Almagest he had pointed out, obliged him to quit Rome precipitately in 1468.
The Almagest was the consummation of Greek astronomy.
His most celebrated work is the Latin version by which alone Ptolemy's Almagest was known to Europe until the discovery of the original Meyan I un-a ts.
The names and orientation of the constellations therein adopted are, with but few exceptions, identical with those used at the present day; and as it cannot be doubted that Ptolemy made only very few modifications in the system of Hipparchus, the names were adopted at least three centuries before the Almagest was compiled.
It is substantially embodied in Ptolemy's Almagest (see Ptolemy).