A/N I'm too lazy to write a big, fat prequel, so here's a summary of it.
Anakin was never found by the Jedi. Palpatine found and bought him, so he became a Sith slave. Since he was six years old he was trained as a Sith Lord. When the Empire took over, the name of Darth Vader became notorious across the galaxy. However, he wore a mask to hide a face. No one knew what he actually looked like.
When he was nineteen, one of the Rebel Alliance was captured and enslaved. Her name was Padme Amidala. The day he saw her face, something in his heart changed. He requested from Lord Sidious to have her, and so he did. At first she hated him, but gradually softened to him. Especially when she discovered that he was just a slave, too. But he never took off the mask in front of her, and she only knew him as Darth Vader. Until certain rebel decided to sabotage Vader's quarters.
In the middle of the night, an explosion wrecked havok through his flat. Padme was unconscious and the building was burning down. His thought was only for her, and so he fled the building carrying her to safety. In only his sleep pants with his lightsabers hung at his hips, he carried her out. And that is how Padme discovered that beneath the armor of Darth Vader was a little boy from Tatooine, Anakin Skywalker. So, they fell in love. And his love for Padme caused him to kill the Emporer.
They both ran away to Naboo after that, leaving everything behind. Bail Organa became the new chancellor and everything was right in the galaxy. Darth Vader had disappeared, and no one connected Anakin Skywalker to him. That is, until a certain rebel arrives on the scene.