(Ἑλένη), the daughter of Timon of Egypt, painted the battle of Issus about the time of its occurrence (B. C. 333). In the reign of Vespasian this picture was placed in the Temple of Peace at Rome. (Ptol. Hephaest. apud Phot. cod. 190, p. 149b. 30, ed. Bekker.) It is supposed by some scholars that the well-known mosaic found at Pompeii is a copy of this picture, while others believe it to represent the battle at the Granicus, others that at Arbela. All that can be safely said is, that the mosaic represents one of Alexander's battles, and that in all probability the person in the chariot is Dareius. (Müller, Archäol. d. Kunst, § 163. n. 1, 6.)
[P.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890