He found out partly in Episode 4 but it can be argued that he figgered it out in Episode 5 or even 6.
Star Wars FOREVER
<3 Zoe Skywalker
Actually, Darth Vader is Luke Skywalker's father
His name is Luke Skywalker because Darth Vader is really Anakin Skywalker.
Luke Skywalker and Darth Vader are 2 different people.
Darth Vader (Anakin Skywalker).
because,Darth Vader is Also Anakin Skywalker who got married to padma Admadola
Yes
Luke Skywalker
Darth Vader
Yes. Princess Leia is Darth Vader's daughter and Luke Skywalker's twin sister.
Darth Vader, who's real name is Anakin Skywalker, has two children, twins. They are Luke Skywalker and Leia Organa (Princess Leia). They were separated at birth after the death of their mother. By a twist of fate, both of them end up fighting against their own father.
Aniakin Skywalker (Darth Vader)
Anakin Skywalker aka Darth Vader