Timanthes in Harpers Dictionary of Classical Antiquities (1898)
（Τιμάνθης). A celebrated Greek painter at Sicyon, contemporary with Zeuxis and Parrhasius, about B.C. 400. The masterpiece of Timanthes was his celebrated picture of the sacrifice of Iphigenia, in which Agamemnon was painted with his face hidden in his mantle (Pliny , Pliny H. N. xxxv. 73). See the illustration under Iphigenia.
Timanthes in Wikipedia
Timanthes of Cythnus (or Sicyon) was an ancient Greek painter of the 4th century BC. The most celebrated of his works was a picture representing the sacrifice of Iphigenia, in which he finely depicted the emotions of those who took part in the sacrifice; however, despairing of rendering the grief of Agamemnon, he represented him as veiling his face. A painting discovered at Pompeii, and now in the Museum at Naples, has been regarded as a copy or echo of this painting (Wolfgang Helbig, Wand gemalde Campaniens, No. 1304).