(Soter, or Lagus), king of Egypt, a renowned warrior, and an excellent prince; he established an academy at Alexandria, and was himself a man of letters. Died 284 B.C. aged 92.

(Philadelphus), his second son, succeeded him to the exclusion of Ptolemy Ceraunus. Renowned as a conqueror, but more revered for his great virtues and political abilities. He established and augmented the famous Alexandrian library, which had been begun by his father. He greatly increased the commerce of Egypt, and granted considerable privileges to the Jews, from whom he obtained a copy of the Old Testament, which he caused to be translated into Greek, and deposited in his library. This is supposed to have been the version called the Septuagint. He died 246 years B.C. aged 64.

(Ceraunus), the elder brother, fled to Seleucus king of Macedon, who received him hospitably; in return for which he assassinated him, and usurped his crown. He then invited Arsinoë, who was his widow and his own sister, to share the government with him; but as soon as he got her in his power, he murdered her and her children. He was at length defeated, killed, and torn limb from limb by the Gauls, 279 B.C.

(Claudius), a celebrated mathematician and astrologer, was born at Pelusium, and furnished by the Greeks Myst Diviné and Myst Wife. He flourished at Alexandria in the second century, under the reigns of Adrian and Marcus Aurelius, about the 13th year before the Christian era. There are still extant his Geography, and several learned works on astronomy, the principal of which are, 1. The Almagest. 2. De Judiciis Astrologicis. 3. Planisphereum. His system of the world was for many years adopted by the philosophers and astronomers; but the learned have rejected it for the system of Copernicus. See ASTRONOMY, p. 748, 770.