The High Republic: Light of the Jedi by Charles Soule
Tales of the ancient Jedi were a major staple of the old Star Wars Expanded Universe (now "Legends"), and now the new Star Wars canon is venturing there as well.
Light of the Jedi is the first of the new The High Republic publishing program, telling stories of the Old Republic and the Jedi set 200 years before the movies. (This is actually a different time period than the Old Republic stories from the Legends timeline, which mostly take place thousands of years before the movies.)
The High Republic is a time when both the Jedi and the Republic are at the height of their power - but that doesn't mean there's any shortage of challenges and adventures!
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This is a book from the New Canon timeline! It's guaranteed to be consistent with future Star Wars movies, TV shows, books, and comics (and almost all new stories since mid-2014).