Before Christianity, Greeks buried their dead with coins in their mouths to pay the ferryman in the afterlife. But coins were only invented at the end of the 7th century BCE. Was this a tradition that postdated the invention of coinage, or an existing tradition adapted to include coinage?

Originally, the Greeks buried their dead in mass graves. This stopped around 1000 BC, at which point individual graves became more prevalent in most of Greece, except in Athens, where cremation was more common. Furthermore, the figure of the Ferryman Charon would not appear until around 500 BC, around a century after the introduction of the drachma in Athens.

Before that, most funeral rites were done by relatives of the deceased, normally women, in three parts:

The prothesis (laying out of the body), the ekphora (funeral procession), and the interment of the body or cremated remains of the deceased.

After being washed and anointed with oil, the body was dressed and placed on a high bed within the house. During the prothesis, relatives and friends came to mourn and pay their respects. Lamentation of the dead is featured in Greek art at least as early as the Geometric period, when vases were decorated with scenes portraying the deceased surrounded by mourners. Following the prothesis, the deceased was brought to the cemetery in a procession, the ekphora, which usually took place just before dawn. Very few objects were actually placed in the grave, but monumental earth mounds, rectangular built tombs, and elaborate marble stelai and statues were often erected to mark the grave and to ensure that the deceased would not be forgotten.

The coins in the toms of the deceased appeared before Charon himself, in some of the tombs in Cyprus, dating around 600 BC. Charon’s Obol continued through most of Greek and Roman history, even reaching place like the Iberian Peninsula. In cities such as Athens, where cremation was still common, coins could be found stuck to the jawbones in burials, giving strong evidence to the fact that coins were placed in the mouth, and not on the eyes.

Sources:
https://www.britannica.com/topic/cremation
https://www.britannica.com/topic/Charon-Greek-mythology
https://www.britannica.com/topic/shaft-graves
https://www.britannica.com/topic/drachma
https://www.metmuseum.org/TOAH/hd/dbag/hd_dbag.htm
https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0104%3Aentry%3Dcharon-bio-1
kyprioscharacter.eie.gr/en/scientific-texts/details/numismatics/history-of-study-of-coinage-of-cypriote-kingdoms-brief-evaluation-of-important-achievements
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