The phrase 'the Old Republic' was first uttered by Obi-Wan Kenobi in 1977's Star Wars: A New Hope, in reference to the days before the Galactic Empire, but eventually came to refer more specifically to a period that ran from the Republic's founding to roughly 1,000 years before the Skywalker Saga. However, there is one era of Legends storytelling that fans remain eager to see explored anew that is yet to feature in any Disney-produced Star Wars content: the Old Republic. And as Disney has fleshed out their new Star Wars universe, various aspects of the Legends continuity have been gradually reimagined and reintroduced to the new canon. While the films and the animated Star Wars: The Clone Wars TV series remained canon, the Expanded Universe that had been developed through various books, comics, video games and other media was designated 'Legends' and replaced with a new Star Wars timeline.
The Star Wars canon has undergone a radical reinvention since Disney's acquisition of Lucasfilm in 2012.