In Greek mythology, a jar held the evils released by Pandora.
The ancient Greek story does not originally describe a box. Hesiod’s Works and Days uses the word pithos, meaning a large storage jar or earthenware container. Pandora opened it, releasing troubles into the world, while something remained inside.
The familiar phrase “Pandora’s box” arose much later through translation. In the sixteenth century, the Renaissance humanist Erasmus rendered the Greek container as a Latin pyxis, or box, helping establish the wording that became standard in European languages.
The jar was a large household or agricultural vessel, not necessarily a small personal container. Modern retellings often picture a decorated box because that image matches the later expression, but the earliest surviving literary account points to a jar.