Like many of the ancient Jedi, Yoda's past remains a closely guarded secret. According to Yoda's own words, he trained Jedi for more than 800 years, and it is known that he was about 900 upon his death. Yoda proved a stern instructor and would only teach the most serious and committed students. Among these was Obi-Wan Kenobi, a young and reckless youth who proved incredibly strong in the Force.

While training his students, Yoda demanded that they improve their bodies as well as their minds. Aspiring Jedi endured marathons and learned to balance their bodies in strange ways. They also expanded their abilities to levitate objects and sense the future.

Despite his vast power, Yoda was forced into hiding by Emperor Palpatine's campaign against the Jedi. Yoda retreated to Dagobah, He uses the Force and the planet's own natural defenses to discourage visitors. He also used the Force to monitor progress of Luke Skywalker and Leia Organa, the children of the Dark Lord of the Sith, Darth Vader.

After escaping almost certain death from a wampa ice creature on Hoth, Luke sees Ben Kenobi in a vision, telling him to go to the Dagobah system to continue his Jedi training with Yoda.

By the time Luke encounters him in the bogs of Dagobah, Yoda is nearly 900 years old and walks stooped over with the help of a gimer stick. He subsists on things that nature offer him, eating plants and fruits and fungi, and building his home of mud, sticks and stones.

After some debate, Yoda agreed to teach the boy. During the arduous training, Yoda lectured young Skywalker about the Force while Luke performed rigorous physical and mental exercises. As part of his teachings, Yoda warned Luke of the dark side, which had claimed Vader.

Yoda's path to Jedi wisdom seems simple, yet profound. He makes his students unlearn what they had been taught, helping them to tune in to the subtle world around them to learn its truths. "A Jedi uses the Force for knowledge. Never for attack," he tells them.

Yoda lectures young Skywalker about the Force while Luke performs rigorous physical and mental exercises. Yoda especially cautions him against the easy path of anger and the lure of the dark side of the Force.

When ordered to undertake a particularly daunting task, Luke says he'll try. "No! Try not," Yoda says. "Do. Or do not. There is no try." Despite Yoda's plea, Luke leaves before his training is complete when he senses that his friends are in danger.

As his powers expanded, Luke learned to glimpse the future and discovered that his friends were in great danger. Despite Yoda's advice, Luke left Dagobah and traveled to Cloud City. There, Luke almost fell victim to Vader, much as Yoda had feared.

A year later, Luke returned to Dagobah to continute his training with Yoda. The venerated Jedi Master, however, was near death. He informed Luke that he had to confront Vader once more before he passed away. A short time later, after the Battle of Endor, Yoda, Obi-Wan Kenobi, and Anakin Skywalker, appeared before Luke as luminescent beings at one with the Force.