Oathkeeper designated a specific position inside the Galactic Empire's Imperial Senate. According to time-honored custom, either the Oathkeeper or the Speaker, a position occupied by Grand Vizier Mas Amedda, would commence each senate meeting.
The Oathkeeper was referenced inside the 2023 reference work, Star Wars: Dawn of Rebellion: The Visual Guide, authored collaboratively by Pablo Hidalgo and Emily Shkoukani.