What were the earliest Star Wars Original Trilogy Prequel Stories before the Prequel trilogy was released?

The question is what could be considered the earliest "prequels" in the old EU before the Prequel trilogy was released. No post-1999 stuff.

This kind of applies. From the 1979 Marvel comic Star Wars Annual 1: The Long Hunt. This panel was turned into the novella Skyewalkers.

I thought he meant in-universe.

Azronger wrote:I thought he meant in-universe.

I did.

The adventure Obi-Wan goes in this comic happens "years" before the events of ANH according to Leia