The relationship between secret Sith Lord Darth Sidious/Supreme Chancellor Sheev Palpatine and Jedi Knight Anakin Skywalker.
They are formerly allies and former Master and Apprentice.
Palpatine met Anakin Skywalker shortly after the Battle of Naboo, where he would "Watch [Anakin]'s career with great interest." Following this, Palpatine has poised himself as an understanding figure towards Anakin, who also felt Palpatine was the father he never had, especially since the Supreme Chancellor seemed to support him when Obi-Wan and the other Jedi could not. However, throughout all the years, Palpatine was grooming ANakin to become his apprentice, and has been manipulating him since he was a child.
End of the Clone Wars
Palpatine was eventually successful at the end of the Clone Wars, where Anakin fell to the Dark Side and became Palpatine's apprentice, especially when Palpatine told Anakin that his wife was dead because she was killed in his anger. Throughout the years, Vader followed Palpatine's every whim. However, the relationship fell through when, as Darth Vader, he learned that Padme had not died in childbirth and had actually given birth to their children. In the end, Vader redeemed himself when he turned on Palpatine in order to save his son, Luke.