The onion, Allium cepa, is one of the most ancient of cultivated food plants, grown across the old world since prehistory. Nowhere was it more freighted with meaning than in ancient Egypt, where its concentric layers, read as circles within circles, made it a symbol of eternity, and where onions were placed in tombs, painted on temple walls and pressed into the eye-sockets and body cavities of the dead. Egyptians were said to swear oaths upon the onion, and Roman writers mocked them for it. The Israelites in the desert numbered the onions of Egypt among the foods they longed for.
Herodotus, touring Egypt centuries after the pyramids were built, records that an inscription on the Great Pyramid itself detailed the vast sums spent on radishes, onions and garlic to feed the labourers who raised it, a claim historians treat cautiously since the inscription itself has never been found, though it fixed the onion in the popular imagination as the food of the pyramid-builders as much as of the pharaohs entombed inside them. The mummy of Ramesses IV was found with small onions placed in its eye sockets, apparently the only instance of the practice used to this degree on a royal mummy, a striking physical case of the burial symbolism this article describes.