The standard history of Star Wars publishing begins in 1991. It is a convenient story and it skips fourteen years of material that was, at the time, the only Star Wars anybody could get between films.
The comics ran the whole time
Marvel published Star Wars monthly from 1977 to 1986 — one hundred and seven issues plus three annuals. That is nine years of continuous serialised storytelling, most of it produced in the gaps between the films, and for a large number of readers in that period it simply was Star Wars. It also had to invent a great deal, because it was frequently writing ahead of films that had not been made yet.
The novels arrived early and then stopped
After Foster’s 1978 Splinter of the Mind’s Eye, Brian Daley wrote three novels about Han Solo and Chewbacca operating in the Corporate Sector: Han Solo at Stars’ End (Del Rey, April 1979), Han Solo’s Revenge (October 1979) and Han Solo and the Lost Legacy (1980). They are caper novels. They are also, deliberately, set far enough from the films that they could not contradict them.
L. Neil Smith followed with three Lando Calrissian novels in 1983 — Lando Calrissian and the Mindharp of Sharu, …and the Flamewind of Oseon and …and the Starcave of ThonBoka — which are considerably stranger than anything that would be commissioned today. Then the novels stopped, and for most of the rest of the decade there were none.
The radio dramas
Daley also wrote the scripts for the National Public Radio adaptations: the first broadcast in 1981, and a second series based on The Empire Strikes Back that debuted on 14 February 1983. They are considerably longer than the films and they use the extra hours the way prose does — on conversation, on interiority, on the parts a two-hour cut had to lose.
And a book that indexed all of it
In 1984 Del Rey published Raymond L. Velasco’s A Guide to the Star Wars Universe, an alphabetical reference to roughly nine hundred and fifty entries. It is the first attempt to treat all this scattered material as one body, which is a small thing and also the beginning of an idea that dominates the next thirty years.
Why it matters
Two reasons. First, because it corrects a common assumption: Timothy Zahn did not invent Star Wars publishing in 1991, he revived it, and what he revived had an established shape. Second, because this early material is where several habits of the shelf were set — the preference for the margins over the main plot, the tendency to give supporting characters their own books, and the pragmatic understanding that the films outrank you and always will.
Nearly all of it now sits under the Legends banner. Almost none of it is the first thing anyone recommends. It is still the foundation the 1991 boom was built on.