When did Star Wars Chapter 2 become Episode V?

from blog Terence Eden’s Blog, | ↗ original
↗ original
As every good geek knows, Star Wars Episode IV A New Hope was originally called… "Star Wars". That's it. No subtitle. No episode number. When Empire Strikes Back came out, it was called "Star Wars Episode V" - which necessitated rewriting history and calling the original film "Episode IV". But at what point did the second Star Wars movie...