The aegis ( ; aigís), as stated in the Iliad, is a device carried by Athena and Zeus, variously interpreted as an animal skin or a shield and sometimes featuring the head of a Gorgon. There may be a connection with a deity named Aex or Aix, a daughter of Helios and a nurse of Zeus or alternatively a mistress of Zeus (Hyginus, Astronomica 2. 13). The modern concept of doing something "under someone's aegis means doing something under the protection of a powerful, knowledgeable, or benevolent source. The word aegis is identified with protection by a strong force with its roots in Greek mythology and adopted by the Romans; there are parallels in Norse mythology and in Egyptian mythology as well, where the Greek word aegis is applied by extension. Etymology The Greek aigis, has many meanings including: "violent windstorm", from the verb aïssō (word stem aïg-) = "I rush or move violently". Akin to kataigis, "thunderstorm". The shield of a deity as described above. "goatskin coat", from treating the word as meaning "something grammatically feminine pertaining to goat": Greek aix (stem aig-) = "goat", + suffix -is (stem -id-). The original meaning may have been the first, and Zeus Aigiokhos = "Zeus who holds the aegis" may have originally meant "Sky/Heaven, who holds the thunderstorm". The transition to the meaning "shield" or "goatskin" may have come by folk etymology among a people familiar with draping an animal skin over the left arm as a shield. In Greek mythology The aegis of Athena is referred to in several places in the Iliad. "It produced a sound as from myriad roaring dragons (Iliad, 4.17) and was borne by Athena in battle ... and among them went bright-eyed Athene, holding the precious aegis which is ageless and immortal: a hundred tassels of pure gold hang fluttering from it, tight-woven each of them, and each the worth of a hundred oxen." Virgil imagines the Cyclopes in Hephaestus' forge, who "busily burnished the aegis Athena wears in her angry moods—a fearsome thing with a surface of gold like scaly snake-skin, and the linked serpents and the Gorgon herself upon the goddess's breast—a severed head rolling its eyes", furnished with golden tassels and bearing the Gorgoneion (Medusa's head) in the central boss. Some of the Attic vase-painters retained an archaic tradition that the tassels had originally been serpents in their representations of the aegis.