Siwa and the oracle of Ammon: Alexander's desert journey
The oracle of Zeus Ammon in the Siwa oasis: the ram-horned god, the lost army of Cambyses and Alexander the Great's visit to the shrine in 331 BC.
In Egypt's Western Desert, hundreds of kilometres from the Nile valley, the oasis of Siwa housed one of the most respected oracular sanctuaries of the ancient Mediterranean. There Amun was worshipped, the great god of Thebes, whom the Greeks called Zeus Ammon and depicted with ram's horns. His fame reached Greece as early as the archaic period, but it was the visit of Alexander the Great that made him legendary.
An Egyptian oracle for the Greeks
The Greeks came to know Ammon mainly through Cyrene, the colony founded on the Libyan coast. Pindar composed a hymn in his honour and, according to Pausanias, dedicated it to the statue of the god that stood at Thebes in Boeotia. Among the Greeks who consulted the oracle the sources mention Cimon and the Spartan Lysander, and Croesus himself, according to Herodotus, included it in his famous test of the oracles.
Herodotus also relates that Cambyses, the Persian king who conquered Egypt, sent an army against the Ammonians and that the soldiers vanished in the desert, overwhelmed, according to the local account, by a sandstorm. The story has fired the imagination of explorers and treasure hunters for centuries, but the fate of that army remains unknown.
Alexander's march
In the winter of 332 to 331 BC, after taking possession of Egypt and founding Alexandria, Alexander decided to reach the oasis. Ancient historians, among them Arrian, Plutarch, Diodorus and Curtius Rufus, describe a difficult crossing, with water running out and tracks erased by the wind. Arrian reports two different traditions: according to Ptolemy the column was guided by two snakes that uttered a voice, according to Aristobulus by two ravens.
The motives for the journey are debated. Arrian writes that Alexander wished to emulate Perseus and Heracles, who according to legend had consulted the same god, and that he traced part of his own descent to Ammon, just as the myths traced that of the two heroes to Zeus. Personal devotion and political calculation were thus intertwined.
The priest's greeting
What happened inside the sanctuary remains partly a mystery, because Alexander entered alone. Plutarch says that the priest greeted him as son of the god, and also reports a more prosaic explanation: wishing to call him “my son” in Greek, the priest supposedly got one letter wrong, uttering words that sounded like “son of Zeus”. Plutarch adds that Alexander wrote to his mother Olympias that he had received secret answers, which he would reveal to her on his return.
Diodorus describes how the god replied: his image, adorned with precious stones, was carried in procession on a gilded boat by many priests, who moved in the direction indicated, it was believed, by a divine nod. It is the same kind of processional oracle documented in the temples of the Nile valley.
After Alexander
After the king's death, his successors struck coins showing Alexander with the ram's horns of Ammon, a visible sign of the divine sonship claimed at Siwa. In the oasis remain the ruins of the oracle temple on the rock of Aghurmi and those of the temple built by the pharaoh Nectanebo II at Umm Ubayda, a short distance away.
By Strabo's time, in the first century BC, the oracle was almost abandoned, because the Romans preferred the Sibylline oracles and Etruscan haruspicy. Yet the memory of that conversation in the desert endured, helping to turn a Macedonian king into a semi-divine figure and leaving history one of its most enigmatic scenes.