ÆGIS, in the ancient mythology, a name given to the shield or buckler of Jupiter and Pallas.
The goat Amalthea, which had suckled Jove, being dead, that god is said to have covered his buckler with the skin thereof; whence the appellation ægis, from æis, ægis, she-goat. Jupiter, afterwards restoring the beast to life again, covered it with a new skin, and placed it among the stars. As to his buckler, he made a present of it to Minerva; whence that goddess's buckler is also called ægis.
Minerva, having killed the Gorgon Medusa, nailed her head in the middle of the ægis, which henceforth had the faculty of converting into stone all those who looked thereon; as Medusa herself had done during her life.
Others take the ægis not to have been a buckler, but a cuirass, or breast-plate: and it is certain the ægis of Pallas, described by Virgil, En. lib. viii. ver. 435, must have been a cuirass; since that poet says expressly, that Medusa's head was on the breast of the goddess. But the ægis of Jupiter, mentioned a little higher, ver. 354, seems to have been a buckler: the words
Cum sepe nigrantem
Ægida conuteret dextra, agreeing very well to a buckler; but not at all to a cuirass or breast-plate.
Servius makes the same distinction on the two passages of Virgil: for on verse 354, he takes the ægis for the buckler of Jupiter, made, as above-mentioned, of the skin of the goat Amalthea; and on verse 435 he describes the ægis as the armour which covers the breast, and which in speaking of men is called cuirass, and ægis in speaking of the gods. Many authors have overlooked these distinctions for want of going to the sources.