Originally Posted by samwiseb
I'm not very familiar with SW at that stage of conception. My understanding though is that when Lucas began shopping his idea around there was just one script/treatment, which upon further revision he began working the first third of that script into what eventually became the movie script.
I don't know at what stage he began conceiving SW as a multi-generation saga, although presumably that idea was in full force by the time Empire was greenlit.
It was before TESB. I got the book "The Art Of Star Wars" which has the complete ANH script in it when it came out, even then, ANH was the actual title and it was considered Episode IV. So we're talking late 1977/early 1978.