Lagus

• the father of Ptolemy I. king of Egypt: regia Lagi, Luc. 10, 527: famosa moenia Lagi, Juv. 6, 83: flumina Lagi, i. e. Nilus, Sil. 17, 592.—Hence,
• II Lāgēus, a, um, adj., of or belonging to Lagus, Lagian, poet. for Egyptian: Nilus, Luc. 1, 684; cf. amnis, Sil. 1, 196: litora, Mart. 10, 26, 4: ratis, Sil. 10, 322.

(Λάγος).

1. The father, or reputed father, of Ptolemy, the founder of the Egyptian monarchy. He married Arsinoe, a concubine of Philip of Macedon, who was said to have been pregnant at the time of their marriage, on which account the Macedonians generally looked upon Ptolemy as in reality the son of Philip. (Paus. 1.6.2; Curt. 9.8; Suidas. s. v. Λάγος.) From an anecdote recorded by Plutarch (De cohib. Ira, 9, p. 458), it is clear that Lagus was a man of obscure birth; hence, when Theocritus (Idyll. 17.26) calls Ptolemy a descendant of Hercules, he probably means to represent him as the son of Philip. Lagus appears to have subsequently married Antigone, niece of Antipater, by whom he became the father of Berenice, afterwards the wife of her step-brother Ptolemy. (Schol. ad Theocr. Id. 17.34, 61.)

2. A son of Ptolemy I. by the celebrated Athenian courtezan Thais. (Athen. 13.576e.) [E.H.B]

(Λάγος). A Macedonian who married Arsinoë, a concubine of Philip of Macedon. She was said to be pregnant at the time of the marriage, so that their son Ptolemy, who afterwards founded the Egyptian monarchy, was by many regarded as the son of Philip (Pausan. i. 6. 2). See Ptolemaeus.

• Paus. 1.1.1, Paus. 1.6.2, Paus. 6.3.1