Well, oddly enough, your question kind of answers itself. The word "Robot" came from a Czech word that translates to, "servitude" or "to serve." This turned into the 1921 play, "R.U.R," which stands for, Rosumovi Univerzální Roboti (Rossum’s Universal Robots) (I borrowed that translation/name of the book from Wikipedia).

This is quite probably the first time a robot as we understand it (and as you described it) appeared in fiction.

Automatons occur in fiction at least as far back as Greek mythology: Hephaestus created such creatures to assist him at his forge.

There are also BCE acounts of such things in the Middle East and Asia.