Yoda

Yoda was a powerful Jedi Master. During the Clone wars era, he triumphed a lot. Shortly after Mace Windu and 4 other Jedi fought Sheev Palpatine, who was revealed to be a Sith and were all killed by Palpatine, Yoda fought the newly crowned Emperor, hoping to stop him. However Master Yoda was defeated, and retreated into exile.