Cosinga Palpatine's offspring included the first brother of Palpatine, who was one of at least three male children. Cosinga Palpatine, an aristocrat from Naboo and the head of House Palpatine, fathered these children with his wife. The eldest of these brothers, known by the family name Palpatine, ascended to become a Dark Lord of the Sith as Darth Sidious, a Senator representing Naboo, the Supreme Chancellor of the Republic, and ultimately the Emperor ruling the galaxy.
The younger Palpatine siblings harbored resentment towards their older brother but were the source of pride for their father, embodying qualities that his eldest son lacked. Conversely, the eldest Palpatine viewed them with disdain, labeling them as "well-behaved" and scorning their lack of the grand ambition he possessed.
The younger brothers were present alongside their father, mother, sisters, and bodyguards during the retrieval of their elder brother from Chandrila aboard the Palpatine family yacht. Following the starship's departure from Chandrila, Palpatine committed a massacre, killing his family, including his youthful brothers.
Each time his Sith master, Darth Plagueis, pushed him to vividly remember the murders as part of his dark side training, Palpatine recalled the lifeless bodies of his siblings lying on the starship's floor.