Per´tinax, Pub´lius Hel´vius. A Roman emperor after the death of Commodus. He was descended from an obscure family, and for some time was employed in drying wood and making charcoal. He entered on a military life and by his valor rose to offices of the highest trust, and was made consul. At the death of Commodus he was selected to succeed to the throne. His patriotism gained him the affection of the worthiest of his subjects, but there were some who plotted against him. He was killed by his soldiers, A.D. 193.

Petro´nius Ar´biter. A favorite of the emperor Nero, and one of the ministers and associates of his pleasures and vices. He was made proconsul of Bithynia, and afterwards was honored with the consulship. Eventually he became out of favor with Nero, and resolved to destroy himself, which he did by having his veins opened, A.D. 66. Petronius distinguished himself by his writings as well as by his voluptuousness. He is the author of many elegant compositions, which are, however, often characterized by impropriety of language.

Phæ´dra. A daughter of Minos and Pasiphæ, who married Theseus. She became the mother of Acamas and Demophoon. She brought an unjust accusation against Hippolytus (a son of Theseus before she married him), who was killed by the horses in his chariot taking fright, causing him to be thrown under the wheels and crushed to death. On hearing this Phædra acknowledged the falseness of the charge she had brought against Hippolytus, and hanged herself in despair.

Phæ´drus. A Thracian who became one of the freed men of the emperor Augustus. He translated the fables of Æsop into Iambic verse.

Pha´ethon. A son of the Sun, or of Phœbus and Clymene. According to Hesiod and Pausanias he was son of Cephalus and Aurora, or of Tithonus and Aurora, according to Apollodorus. He is, however, generally acknowledged to be son of Phœbus and Clymene. Phœbus allowed him to drive the chariot of the sun for one day. Phaethon, on receiving the reins, at once showed his incapacity; the horses became unmanageable, and heaven and earth were threatened with a conflagration, when Jupiter struck Phaethon with a thunderbolt, and hurled him into the river Po, where he perished.

Phal´aris. A tyrant of Agrigentum, who treated his subjects with great cruelty. Perillus made him a brazen bull, inside of which he proposed to place culprits, and by applying fire burn them to death. The first to be thus burnt in this manner was Perillus himself. The cruelties practiced by Phalaris were revenged by a revolt of his people, who put him to death by burning him in the bull.

Pha´on. A boatman of Mitylene, in Lesbos. He received a box of ointment from Venus, who had presented herself to him in the form of an old woman. When he had rubbed himself with the unguent he became beautiful, and Sappho, the celebrated poetess, became enamored with him. For a short time he devoted himself to her, but soon treated her with coldness, upon which she threw herself into the sea and was drowned.

Pharnaba´zus. A satrap of Persia who assisted the Lacedæmonians against the Athenians, and gained their esteem by his devotion to their cause.

Pha´ros. A small island in the bay of Alexandria, on which was built a tower which was considered one of the seven wonders of the world. It was erected in the reigns of Ptolemy Soter and Ptolemy Philadelphus, the architect being Sostratus, the son of Dexiphanes.

Pharsa´lia. A town of Thessaly, famous for the great battle fought there between Julius Cæsar and Pompey, in which the former obtained the victory.