surnamed PERGAEUS,from Perga in Pamphylia, his native city, a mathematician educated at Alexandria under the successors of Euclid. He was born in the reign of Ptolemy Euergetes (Eutoc. Comm. in Ap. Con. lib. i.), and died under Philopator, who reigned B. C. 222-205. (Hephaest. apud Phot. cod. cxc.) He was, therefore, probably about 40 years younger than Archimedes. His geometrical works were held in such esteem, that they procured for him the appellation of the Great Geometer. (Eutoc. l.c.) He is also mentioned by Ptolemy as an astronomer, and is said to have been called by the sobriquet of e, from his fondness for observing the moon, the shape of which was supposed to resemble that letter.
[W.F.D]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890