The story
For centuries in western Europe, educated people read Latin, but few could read Greek. One popular story says medieval scribes copying old manuscripts would reach a Greek passage and write a note: “Graecum est; non legitur”—it’s Greek; it can’t be read. Scholars think that’s a likely root, but no one has proved it.
The English version shows up in 1566. The poet George Gascoigne translated an Italian comedy as Supposes and added a line the original didn’t have: “This geare is Greeke to me.”
Others picked it up. Robert Greene has a character say “Tis Greeke to mee” in a play printed in 1598.
The most famous version comes from Shakespeare’s Julius Caesar, written around 1599. Cassius asks Casca what the great speaker Cicero said. Casca replies that he spoke Greek, and those who understood him smiled at one another, “but, for mine own part, it was Greek to me.” The joke works twice: Cicero really was speaking Greek.
