The original trilogy follows the struggle of the Rebel Alliance, an organized resistance formed to combat Emperor Palpatine's Galactic Empire, as well as the resurgence of the Jedi Order.
A New Hope begins with the Empire nearing completion of the Death Star, which will allow the Empire to crush the rebels. Palpatine's apprentice Darth Vader captures Princess Leia, a member of the rebellion who has stolen the plans to the Death Star and hidden them in the astromech droid R2-D2, who, along with his protocol droid friend C-3PO, escapes to the desert planet Tatooine, where they are bought by Luke Skywalker and his step-uncle and aunt. While Luke is cleaning R2, he triggers a message put into him by Leia, who asks for assistance from the legendary Jedi Obi-Wan Kenobi. Luke later assists them in finding Kenobi, who is now passing as an old hermit under the alias Ben Kenobi. Obi-Wan and Luke hire the smuggler Han Solo and his Wookiee co-pilot Chewbacca to take them to Alderaan, Leia's homeworld, which they find has been destroyed by the Death Star, which captures them. However, the four of them pull of a rescue of Leia, and Kenobi sacrifices himself so they can escape with the plans. Luke, guided by the Force, fires the shot that destroys the Death Star during the Battle of Yavin.
Three years later, after escaping an attack by the Empire, Luke travels to find the Jedi Master Yoda, now living in exile on the swamp planet Dagobah, to begin his Jedi training. However, Luke's training is interrupted when Vader lures him into a trap by capturing Han and his friends at Cloud City. During a fierce duel, Vader reveals that he is Luke's father and attempts to turn him to the dark side of the Force. Luke refuses and escapes. Six months later, after they rescue Han from the crime lord Jabba the Hutt, returns to Yoda to complete his training, only to find the 900-year-old Jedi Master on his deathbed. Before he dies, Yoda confirms that Vader is Luke's father. Kenobi's Force ghost tells Luke that he must confront his father once again before he can become a Jedi, and that Leia is his twin sister.
On the forest moon of Endor, the Rebels manage to destroy the shield generator of the second Death Star with the help of the native Ewoks. Luke is taken aboard the Death Star to meet with Vader and Palpatine. Luke engages Vader in a duel as the Emperor watches; both Sith Lords intend to turn Luke to the dark side and take him as their apprentice. Luke succumbs to his anger and brutally overpowers Vader, but controls himself at the last minute and spares Vader's life and declares his allegiance to the Jedi. Enraged, Palpatine then blasts Luke with Force lightning, but a moved Vader kills the Emperor, suffering mortal wounds in the process. After thanking Luke for bringing him back to the light side, Anakin Skywalker dies in his son's arms while the Rebels succeed in destroying the second Death Star.
The prequel trilogy explores the backstory of the fall of the Republic, the Clone Wars, Palpatine's rise to power, and Anakin Skywalker's fall from grace.
32 years before the Battle of Endor, the corrupt Trade Federation set up a blockade of battleships around the planet Naboo. Darth Sidious had secretly planned the blockade to give his alter ego, Senator Palpatine, a pretense to overthrow and replace the Supreme Chancellor of the Republic. At the Chancellor's request, the Jedi Qui-Gon Jinn and his apprentice, Obi-Wan Kenobi, are sent to Naboo to negotiate with the Federation, but are forced to instead help the Queen of Naboo, Padmé Amidala, escape from the blockade and plead her planet's crisis before the Republic Senate on Coruscant. When their starship is damaged, they land on Tatooine for repairs, where Qui-Gon discovers a young Anakin Skywalker, whom Qui-Gon comes to believe that Anakin is the prophesied Chosen One to bring balance to the Force, and he helps liberate the boy from slavery so he can be trained as a Jedi. The Jedi Council, led by Yoda, sense danger in training Anakin, but reluctantly allow Obi-Wan to train him after Qui-Gon is killed by Palpatine's apprentice, Darth Maul, during the Battle of Naboo.
T10 years later, the Jedi Order becomes involved in the Clone Wars between the armies of the Republic and the Confederacy of Independent Systems, which Palpatine secretly engineers to destroy the Jedi Order and lure Anakin into his service. At the same time, Anakin and Padmé fall in love and secretly wed, and eventually Padmé becomes pregnant. Anakin has a vision of Padmé dying in childbirth, and Palpatine convinces him that the dark side of the Force holds the power to save her life. Desperate, Anakin submits to Palpatine's Sith teachings and is renamed Darth Vader.
While Palpatine re-organizes the Republic into the tyrannical Empire, Vader participates in the extermination of the Jedi Order, culminating in a duel between himself and Obi-Wan on the volcanic planet Mustafar. Obi-Wan defeats him, severing his limbs and leaving him to die. Palpatine arrives shortly afterward and saves Vader by placing him into a cyborg suit. At the same time, Padmé dies while giving birth to twins Luke and Leia. Obi-Wan and Yoda, two of the only remaining Jedi, agree to separate the twins and keep them hidden from both Vader and the Emperor until the time is right.