The eagle of Zeus and Jupiter: messenger, abductor, standard of Rome

For the Greeks the eagle was simply «the bird of Zeus». Flying higher than any other creature and, so it was believed, gazing at the sun without lowering its eyes, it seemed made to stand beside the lord of the sky and the thunderbolt. From this association arose myths, omens, works of art and finally one of the most enduring political symbols in Europe, passed from Olympia to the Roman legions and then to later empires.

Omens and myths of the sky

In the Iliad the eagle appears several times as a sign sent by Zeus. In the twelfth book an eagle clutching a still-living snake in its talons appears to the Trojans as they storm the Achaean wall, and Polydamas interprets it as an announcement of defeat. In the last book, when Priam prepares to go to Achilles to ransom the body of Hector, the god sends an eagle on the right as a favourable sign.

Two myths show the eagle as the instrument of divine will. According to Hesiod, in the Theogony, an eagle sent by Zeus devoured every day the liver of the chained Prometheus, which grew back during the night. In a different story, told among others by Ovid in the Metamorphoses, Zeus himself takes the form of an eagle to carry off the young Trojan Ganymede and make him cupbearer of the gods on Olympus.

Delphi, Olympia and the god's sceptre

A tradition reported by Strabo and other authors says that Zeus released two eagles from opposite ends of the earth: they met at Delphi, which was thus recognised as the centre of the world. For this reason the omphalos, the stone that marked the navel of the earth in the sanctuary of Apollo, was sometimes depicted flanked by two eagles, and the legend accompanied the prestige of the oracle for centuries.

In the gold and ivory statue of Zeus at Olympia, the work of Phidias and counted among the seven wonders of the world, the god held in his left hand a sceptre topped by an eagle, as Pausanias recalls in his description of the temple. The coins of Elis, the city that administered the sanctuary, also often show the eagle, sometimes in the act of seizing a hare or a snake.

The eagle of the legions

In Rome the eagle passed to Capitoline Jupiter and from him to the army. Pliny the Elder, in his Natural History, records that it was Gaius Marius, during his second consulship in 104 BC, who established the eagle as the sole standard of the legions, in place of the wolves, minotaurs, horses and boars used before. The aquilifer, the soldier who carried it, enjoyed great prestige, and losing it in battle was a terrible disgrace.

The most famous case is that of the three eagles lost in the Teutoburg Forest in AD 9, when the legions of Publius Quinctilius Varus were wiped out. Their recovery became a political goal: Germanicus regained two in the following years, while the third returned only under Claudius. The standards lost by Crassus at Carrhae were also returned by the Parthians to Augustus in 20 BC, an event celebrated on the breastplate of the Augustus of Prima Porta.

Finally, the eagle had a role in the funerals of emperors. Cassius Dio and Herodian relate that, during the ceremony of deification, an eagle was released from the top of the pyre, representing the soul of the ruler rising among the gods. From here the symbol passed to the Byzantine and German empires and to many European dynasties, preserving into the modern age the bond between sky and power that the Greeks had attributed to the bird of Zeus.