P.R. Hardie, Imago mundi: cosmological and ideological aspects of the shield of Achilles, The journal of Hellenistic Studies, Vol.105 (1985), pp.11-31
Almost all the instances of celestial imagery in Homer apply to objects of particular significance or value, many have associations of divinity.
In the Iliad this astral imagery clusters particularly thickly around the armour brought to Achilles by Thetis in Book XVIII.
In Homer ‘astoroenta’ means ‘like a star, sparkling’, but the dominant, original meaning of the word is ‘adorned with stars.’
In Virgil: ‘caelestibus armis’
It includes the notions of ‘brought down from the sky’ and ‘divine’.
In early Greek literature the grandest star-shield with the exception of the shield of Achilles, is that of Tydeus in Aeschylus’ Septem 387 ff.
The Euripidean shield presents a combination of the mythological and the cosmological.
The star-shield in scholarship
The god of fire Hephaestos is an allegory of the demiurgic fire which creates the universe; the account of the making of the circular shield is an allegory of cosmogony, of the creation of the spherical universe. The four metals of which the shield is made represent the four elements. The three world divisions of earth, sky and sea, followed by the heavenly bodies. The two cities, one at war and one at peace, are allegories of Empedocles’ cosomological principles of ‘filia’ and ‘neikos’. The five layers of which the shield is constructed represent the five zones into which the earth is divided. Eustathius records an llegorization of the ‘antuts’, the rim, of the shield as the circle of the zodia. The shield is a comprehensive symbol of the cosmos.
The ten bronze circles of the shield of Agamemnon are interpreted as the ten circles of the heavens (the circles of Eudoxus with the addition of the Milky Way and the Horizon).
‘imago mundi’ compare the Greek ‘kosmou mimyma’.
Two types of representations of cosmic shield appear in Hellenistic times. In Pompeiian wall-painting eight versions are known. The most celebrated version is the shield from the Domus Uboni. Similar is the shield of the Casa di Sirico.
Of another type is the shield from the Casa del Criptoportico, where the surface is shown as a mirror, perhaps inspired by a composition of APhrodite mirroring herself in the shield of Ares.
The shield is also displayed on the Sarti fragment.
Otto Brendel in 1936 affirms that there is a connection between the Abukir shield of Aleksander the Great and the shield of Achilles with a zodiac and other astronomical devices.
O.J. Brendel, Der Schild des Achilles, die Antike xii (1936) 285 (eng tr. in id., The visible idea [Washington 1980] 67-82)
In the Dionysiaca Nonnus describes the shield of Dionysus.
The Virgilean shield of Aeneas is taken up almost entirely with the scenes of war.
Clipeus Virtutis of Augustus.
The Athena Parthenos shield.
Alexander, the descendant of Achilles.