During the initial days of the Galactic Empire, Senator Bail Prestor Organa spearheaded the creation of a resistance movement. Leveraging the resources and wealth of Alderaan, including both royal and personal assets, this movement facilitated the establishment of some of the earliest organized resistance cells. Organa secured access to significant firepower and other scarce resources, and his movement proactively sought out like-minded individuals, carefully vetting them before recruitment.
Organa's resistance diligently monitored reports and rumors across the galaxy concerning rebellious and insurgent actions, seeking out successful independent resistance groups that could potentially become allies, or even a surviving Jedi. The units at Organa's disposal were in constant flux. Some operated under his direct command, while others consisted of allied forces willing to provide support through active engagement. Thanks to his influential position, Organa and his movement could mobilize Alderaan military forces and a variety of starships whenever increased firepower was necessary.
The resistance movement led by Organa maintained a clandestine network of secret agents, known as Fulcrums, and influential politicians who were utilized for intelligence gathering and covert missions. Capitalizing on Alderaan's well-known reputation for humanitarian aid, Organa's resistance was able to deploy personnel and starships to conflict zones where the Galactic Empire would typically be suspicious of external involvement.
In 18 BBY, Organa uncovered the activities of the former Jedi Padawan Ahsoka Tano and ultimately recruited her into his organization.
By 5 BBY, Organa's movement had merged with Senator Mon Mothma's network, forming a crucial foundation for the emerging Alliance to Restore the Republic.
In 3 BBY, Organa's adopted daughter Leia became aware of his participation in the escalating rebel activities and eventually became a trusted operative within his organization.