When did Star Wars Chapter 2 become Episode V?

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 become known as Episode V?

I've been reading "The Making of the Empire Strikes Back" by J. W. Rinzler, which I shall quote from extensively.

Originally, it seems that Empire was planned to be Episode Seven!

A very early outline for the Star Wars saga in which the original film is actually Episode Six. Episode I is a “prelude” and the Clone Wars trilogy takes place in Episodes II through IV; Episode V would have been an “Epilogue/Prologue.”

That image is undated, and shows us that the numbering sequence was not fixed beforehand.

After the success of the original film, it was assumed by all involved that the inevitable sequel would be "Part 2"

On July 20 [1977], McQuarrie noted in his calendar, “George says we’ll go to England again. S.W. II.”

Companies were set up with the same name:

To minimize some of the downside potential, in the same way Lucas had formed The Star Wars Corporation for the first film, he created another subsidiary for the sequel: The Chapter II Company. [...] The resultant 100-page contract between Fox and Chapter II was signed on September 21, 1977

All of this was done without much thought of what the story would be, and without so much as a draft script.

To that end, Lucas began story conferencing for Chapter II on November 28, 1977, with veteran science-fiction author and screenwriter Leigh Brackett

As the draft was being written, the title came out:

On January 25, 1978, The Hollywood Reporter leaked the title of the film

(Thanks to ARandomName123 for digging up that scan!)

The original Leigh Brackett draft was completed early in 1978, although it didn't bear the "Empire" title.

Ned Brown of Associated Agency personally delivered Leigh Brackett’s first draft to Andrew Rigrod on February 21, 1978.

There are various scans of that draft floating around the web.

All the scans show that this was an unnamed sequel.

See also the auction for this script where the title is simply "Star Wars Sequel".

George Lucas started rewriting the draft, at which point the timeline gets a little tangled.

Here's an auction for an undated script which allegedly from SFX artist Brian Johnson's collection. It lists the film as as Episode II.

At some point in April 1978, George Lucas had a second draft where "Empire" was Episode V.

So, by this point, was Episode V set in stone? Not quite!

On the 14th of June 1978, a few months after the "Episode V" draft, a company was formed in the UK called "Chapter II Productions Ltd". It was part of a growing network of companies made to help produce the film.

On October 17 [1978], another surreal contract was signed, this time between the American production arm of the Chapter II Corporation and its just-formed English counterpart, Chapter II Productions Limited, so work could begin in earnest in that country.

By October 24th, the fourth draft had the name Episode Five - as can been seen in this script.

OK, the Chapter II Company (USA) was doing a deal with Chapter II Productions (UK) to make Episode V, right? Well, almost!

Courtesy of yet another prop auction, I found these schematics for the Millennium Falcon.

As expected, up in the top is a copyright notice for Chapter II Productions Ltd.

But what's this in the bottom corner?

So, as late as 18th December 1978, Empire Strike Back was still known internally to some parts of the production as Episode II!

I couldn't find any further items where the II / V confusion continued. But I did find another interesting titbit.

On 14th of June 1978, the Chapter II Production company was formed in the UK. The next month, on 24th July 1978, Chapter III Production Ltd was formed!

Evidently they were sufficiently confident that there would be a threequel. The Chapter III © appears on plans for Jabba's throne room.

Hmmmm. Just Jedi? No "Revenge of the"? Interesting!

As far as I can tell, both companies were owned by Lucasfilm and, surprisingly, remained active until relatively recently.

Both Chapter II and III were only dissolved in November 2015, just as The Force Awakens was being released. I assume in a fit of internal housekeeping?

So, there you go, the (slightly) untold story of Star Wars Chapters 2 & 3!