John W. Mollett, An Illustrated Dictionary of Words used in Art and Archaeology (1883)
“ In its primary meaning, a goat-skin. The primitive inhabitants of Greece used the skins of goats and other animals for clothing, and defence. At a later period the Ægis became a protective mantle; the shield of Minerva, beneath which the goddess sheltered those whom she wished to protect from the enemy’s missiles. Later still the Ægis denoted the breastplate of a divinity, in especial that of Jupiter or Minerva, as opposed to the lorica, which was the breastplate of a mere mortal. The ægis bore in its centre the Gorgon’s head, of which the serpents were arranged round the border. ”
