The idea of sexual harassment itself might have been codified in law relatively recently, but the phenomenon has been around for a very long time. Ancient Rome had explicit laws against it: You weren't allowed to "accost, abduct or stalk" anybody, particularly women, if it was "contrary to good morals" (though, of course, this only was the case for upper class women). But explicit protections against sexual harassment, particularly for women at work, have historically been meager at best, or insulting at worst.