William Shakespeare existed in a time and place when writing had just become fashionable, when plays were as regular a form of entertainment for the masses as much as television is today, and he had the means to basically import a whole canon of storylines from throughout Europe (Italy being chief among them) and turn them into the Queen's English.
Having support from the queen, and writing plays for people of all classes (swordfights for the lower class, romance for the upper classes) he was really the original popular artist. The fact that modern American English and British English can understand some of the Queen Elizabeth English that William Shakespeare uses contributes to his longevity.