Lagus_

Lagus of Eordaia was a Macedonian courtier and the father of Ptolemy, the founder of the Ptolemaic dynasty. He married Arsinoe of the Argead dynasty and a concubine of Philip II, king of Macedon, who was said to have been pregnant at the time of their marriage, forming the basis of Ptolemy as the son of Philip; but it is possible that this is a later myth fabricated to glorify the Ptolemaic dynasty. From an anecdote recorded by Plutarch, it is clear that Lagus was a man of obscure birth; hence, when Theocritus calls Ptolemy a descendant of Heracles, he probably means to represent him as the son of Philip. Lagus and Arsinoe also were parents to Menelaus.