system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] How did the Jedi know about the Sith Order of Two?

They would have known about the sith empires from the days of the old republic, but how did they know about Bane's order of two?
gpt
Darth Bane himself was killed by the Jedi in canon. It's possible he mentioned it during the battle that claimed his life. The exact circumstances of how they came to know about it haven't been made known for canon, Legends had a former Sith convert a few hundred years later IIRC.