Palpatine's first brother was one of at least three male children of Naboo aristocrat and head of House Palpatine Cosinga Palpatine and his wife. His eldest brother, known simply by the family cognomen of Palpatine, became a Dark Lord of the Sith as Darth Sidious, Senator of Naboo, Supreme Chancellor of the Republic, and Emperor of the galaxy.
The youngest Palpatines resented their elder brother, but were their father's pride, representing all that his eldest could never be. The latter considered them, in turn, "well-behaved" and held them in contempt for not sharing his vast ambition.
The younger Palpatine brothers were present along with their father, mother, sisters and bodyguards when they took their elder brother from Chandrila in the Palpatine family yacht. After the starship left Chandrila, Palpatine slaughtered his family, including his young brothers.
Palpatine remembered the lifeless forms of his siblings slumped on the starship floor every time his Sith master, Darth Plagueis, urged him to recall the murders in vivid detail as part of his training in the dark side.
- Darth Plagueis (First appearance)