The "Menace Revealed" era of Legends bridged the gap between episodes.

While modern canon often points solely to Palpatine, Legends took 13 years to fully explain that the "Phantom Menace" also referred to the Sith Lords' hidden hand in shadows. Key Story Additions from the Novelization

The Star Wars (1998) comic series explores the missions of Council members like Ki-Adi-Mundi on Tatooine just before the film's events. Key Technical and Cultural Facts

Sidious reflects on the Rule of Two and Darth Bane , who lived approximately 2,000 years prior (later retconned to 1,000 in canon).