i have seen every movie in the theater at its first release and i never saw an episode VI or V or IV until the re-release with all the cgi work added as well as a matter of fact they were called
STAR WARS
THE EMPIRE STRIKES BACK
RETURN OF THE JEDI
with star wars very small on the posters as a border that ran around the huge title at least on Empire .
i did not know what A NEW HOPE was for some time as they also added that title after the prequel's
IF they did have numbers on them everyone in 77 would have wondered were the first three movies got off too ? LOL George did not even have the " first three movies " as a twinkling in his eye at that time so HOW could he have put numerals on them at the time anyway they came about as a tool to help people understand what episode they were about to watch and when EI came out that there were two movies in between phantom and what was soon to be called A NEW HOPE .
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OOPS i lied i never saw CLONE WARS in the theater .