Complete Miniseries
Origin of Thrawn
1st appearance of Eli Vanto
1st appearance of Arihnda Pryce, a Moff of the First Galactic Empire
Origin of Thrawn
Origin of Thrawn in flashback, specifically when he was promoted to Grand Admiral by Palpatine
First meeting of Darth Vader and Thrawn in-story, flashback
1st cameo appearance of Admiral Ar'alani