Obi-Wan Kenobi, later known as Ben Kenobi, was a legendary Human Jedi Master. He received his training from Masters Yoda and Qui-Gon Jinn, and taught both Anakin and Luke Skywalker in the ways of the Force, therefore indirectly forging the foundation stone of the New Jedi Order.

In 32 BBY, he became the first Jedi in approximately 1,000 years to defeat a Sith Lord in combat when he defeated Darth Maul during the Second Battle of Theed, and later defeated (though without killing him) Darth Vader on Mustafar. Kenobi was also one of the last members of the Jedi High Council during the waning days of the Old Republic, one of the few Jedi to survive the Great Jedi Purge, and a master of the Soresu form of lightsaber combat. He fought as a High General for the Galactic Republic during the Clone Wars, earning the sobriquet "The Negotiator", and personally ended the threat of General Grievous.

"Qui-Gon's defiance, I sense in you. Need that, you do not."
―Yoda

"I have a bad feeling about this."
"I don't sense anything."
"It's not about the mission, Master. It's something elsewhere…elusive."
―Obi-Wan Kenobi and Qui-Gon Jinn

"The boy is dangerous. They all sense it. Why can't you?"
―Obi-Wan Kenobi to Qui-Gon Jinn, referring to Anakin Skywalker

"It felt like a dream when Qui-Gon fell."
―Obi-Wan Kenobi to Yoda

"Confer on you the level of Jedi Knight, the Council does. But agree with your taking this boy as your Padawan learner, I do not."
"Qui-Gon believed in him."
"The Chosen One, the boy may be. Nevertheless, grave danger, I fear in his training."
―Yoda and Obi-Wan Kenobi

"Obi-Wan has forgotten ever being a child."
―Thracia Cho Leem

"The legacy of this mission is pain."
―Obi-Wan Kenobi

"The capture of Zan Arbor is the safety of the Galaxy."
―Obi-Wan Kenobi

"Obi-Wan is a great mentor. I am truly grateful to be his apprentice."
―Anakin Skywalker

"I will never join you, Dooku."
―Obi-Wan Kenobi to Count Dooku

"You fought in the Clone Wars?"
"Yes. I was once a Jedi Knight, the same as your father."
―Luke Skywalker and Obi-Wan Kenobi

"I doubt even Master Qui-Gon could've prepared a Jedi for this."
―Obi-Wan Kenobi

"I won't fail you."
"No Anakin, don't fail yourself."
―Anakin Skywalker and Obi-Wan Kenobi

"Who's the more foolish, the fool or the fool who follows him?"
―Obi-Wan Kenobi to Han Solo

"He was deceived by a lie. We all were. It appears that the Chancellor…the Emperor, is behind everything, including the war. Palpatine is the Sith Lord we've been looking for. After the death of Count Dooku, Anakin became his new apprentice."
―Obi-Wan Kenobi to Padmé Amidala

"Ah, yes. The negotiator. General Kenobi. We've been waiting for you."
―General Grievous

"Senator Organa, my Clone troops turned on me. I need help."
"We have just rescued Master Yoda. It appears this ambush has happened everywhere. We are sending you our coordinates."
―Obi-Wan Kenobi and Bail Organa

"I can't watch anymore."
"Destroy the Sith, we must."
―Obi-Wan Kenobi and Yoda

"If you're not with me, then you're my enemy!"
"Only a Sith deals in absolutes. I will do what I must."
"You will try!"
―Darth Vader and Obi-Wan before their duel

"You were the Chosen One!! It was said that you would destroy the Sith, not join them!! Bring balance to the Force, not leave it in darkness! ...You were my brother, Anakin! I loved you!"

"I will take the child and watch over him."
―Obi-Wan Kenobi to Yoda and Bail Organa, referring to Luke

"That wizard's just a crazy old man. I don't think he exists anymore. He died about the same time as your father."
―Owen Lars to Luke Skywalker

His death

Before they could reach their destination, Alderaan was destroyed by the Imperial Super Weapon, the Death Star. The Falcon was captured by the Death Star. Kenobi and the others managed to elude capture, and the others even rescued the captive Princess Leia while Kenobi deactivated the tractor beam so the Falcon could escape.

On his way back to the ship, Kenobi encountered his old student, Darth Vader. Vader had earlier surmised to Grand Moff Tarkin that Kenobi had intended from the beginning to meet him in combat. Kenobi distracted Vader and his stormtroopers in a fierce duel, allowing Luke and the rest of the crew to reach the Falcon. During their battle, Vader mocked Obi-Wan by saying:

"Your powers are weak, old man."
―Darth Vader to Obi-Wan Kenobi

Kenobi cryptically warned Vader:

"You can't win Darth. If you strike me down, I shall become more powerful than you can possibly imagine."
―Obi-Wan Kenobi to Darth Vader

Upon seeing Luke he sacrificed himself for Luke and the Falcon's crew escape. Kenobi let down his guard and concentrated for a moment, vanishing to the spiritual plane; his body disappearing entirely just as Vader's lightsaber, instead of severing his body, passed through his empty robe. It is thought that Kenobi vanished into the force to teach Luke a lesson, about how there is no death, there is only the Force as Yoda had said many years before.