There have been several people named Ptolemy:

• Claudius Ptolemaeus, called Ptolemy, was an ancient Greek geographer and astronomer;
• The Ptolemaic dynasty of ancient Egypt included several kings by that name (for a full list, see that article);
• Ptolemy, a disciple of the Gnostic Valentinius is known only for writing a letter to a wealthy Gnostic lady named Flora, quoted by Epiphanius: see the "Letter to Flora" (http://www.gnosis.org/library/flora.htm).

• Another Ptolemy was a mythological ruler of Thebes, Greece.

• Ptolemaeus Chennus, 2nd century grammarian

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