Gold aureus, 18mm, 7.31gm, issued AD 65/66 Rome mint.
Obv: NERO CAESAR AVGVSTVS, Laureate head right.
Rev: IVPPITER CVSTOS, Jupiter, bare to waist, cloak round lower limbs, seated, left on throne, holding thunderbolt and long sceptre.
References: Sear 1930, RIC 52, BMCRE 67.
Traces of lustre and hair lines..
Custos was the facet of Jupiter as a Guardian of the Emperor. This type was issued in thanks after the failure of the Piso conspiracy in AD 65 (see Tac. Ann. 15.48-74). Tacitus reports that a weapon that was to be used against Nero was dedicated by the Emperor in a temple and inscribed to Jupiter.