In Greek mythology, Pandora originally opened a jar, rather than a box. The earliest surviving Greek account, Hesiod’s Works and Days, describes a large storage jar called a pithos. It contained the evils that later spread through the world.
The familiar “box” arose from a later translation history. The Renaissance humanist Erasmus translated the Greek term into Latin as pyxis, meaning a box or small container. That wording became influential in European retellings and eventually fixed the English expression “Pandora’s box.”
A pithos was a substantial ceramic vessel used in the ancient Mediterranean for storing goods such as grain, oil, or wine. It was not a small jewelry box. The change from jar to box is therefore a translation and transmission issue, not a different version of the myth’s central event.
The proverb now means an action that creates many unforeseen problems. Its mythological setting remains specifically Greek, although later writers and artists adapted both the container and the story’s meaning.