We use the expression “beyond the pale” now as if it had the same meaning as “on the wrong side of the tracks”; that is, socially unfit.
That is an acquired sense. “Pale” means the region or district under the jurisdiction of a governing body, the part figuratively enclosed by a paling or fence.
In English history, “the pale” meant those portions of Ireland, or Scotland, or France which, at various times, were under English jurisdiction. So “beyond (or without) the pale” originally meant nothing more than outside the district ruled by England.
But rogues or even honest men sometimes preferred not to be under the jurisdiction of English laws and would “leap the pale,” thus becoming an outlaw or, in modern usage, a social outcast.