Princess Leia Organa Solo was born to Padme Amidala and (the unknowing) Anakin Skywalker during the events of Revenge of the Sith. Amidala died right after the birth of Leia and her twin brother, Luke, and was adopted by Bail Organa, the then senator for the planet Alderaan to the newly formed Galactic Empire, and the Republic before that. Leia was raised on Alderaan by Bail and his wife, and never told her true heritage as the daughter of the man that became Darth Vader. She became the youngest senator to serve in the Imperial Senate when she replaced her father as senator for Alderaan at the age of 16.
She played an integral part in the formation and victory of the Rebel Alliance against the Empire, serving as almost something of a rallying symbol after her home planet of Alderaan was destroyed by the Empire during the events of A New Hope.
After the Empire was defeated and the New Republic established, Leia went on to marry Han Solo and give him a son, Ben Solo. However, this led to the rise of the First Order.