Prior to the Clone Wars, the Andoan Wars were fought within the sector, during which the Harch Spiverelda government attempted to subsidize their militarization and establish a "Great Harch Prosperity," but was prevented by the Galactic Republic's intervention in their allegiance to the Andoan Free Colonies collection of planets. Later, during the Separatist Crisis, roughly half of the Lambda sector was influenced into seceding from the Republic to the Confederacy of Independent Systems by its representative, Senator and Junior Delegate Po Nudo. However, most of the Andoan Free Colonies and Rintonne remained loyal to the Republic.
The Lambda sector was located in the regions known as the Mid Rim Territories and the Slice. It contained the Ando system, the site of the aquatic world of the same name, which was connected via hyperspace routes to the astronomical objects Mon Gazza and Leritor, as well as the astronomical object Rintonne. It also contained the planet Zolan.
Over two decades prior to the Clone Wars fought between the Galactic Republic and Confederacy of Independent Systems, during the Andoan Wars fought within the Lambda sector, the sector's Spiverelda totalitarian government of Aqualish led an effort to suppress the Andoan Free Colonies, a collection of planets situated within the Lambda sector who were loyal to the Republic. During the conflict, the Spiverelda received support from the Harch species' ruling nests of their home planet of Secundus Ando, whose industry was altered in favor of warfare. However, the Republic later intervened in the conflict as they spared and sided with the Free Colonies, which resulted in the prevention of both the ruling nests' subsidization of their militarization as well as their desired wishes of a "Great Harch Prosperity."
Sometime later, amid the time of the Trade Federation's invasion of the planet Naboo in 32 BBY, the planet Ando was represented in the Republic Senate by Aqualish Senator and Junior Delegate Po Nudo, whose allegiance to the democratic government had continously shifted throughout the duration of his political tenure. However, sometime after the outbreak of the Separatist Crisis, a secessionist period led by fallen Jedi Master Count Dooku, the leader of the Confederacy of Independent Systems, a period of turmoil occurred on Ando that left the rest of the galaxy staggered. As a result, roughly half of the Lambda sector, including the Andoan Hyper-Communications Cartel, was influenced into secession from the Republic to the Confederacy by Senator Nudo, while most of the Andoan Free Colonies and the astronomical object Rintoone remained loyal to the Republic.
The waterworld of Ando located in the Lambda sector was the homeworld of the aquatic Aqualish species. It was also the home of Senator Po Nudo, who represented the planet and the rest of the sector in the Republic Senate during the last decade of the Republic Era.
The Lambda sector was first mentioned in the new Star Wars canon in Rise of the Separatists, a 2019 supplement to Fantasy Flight Games' series of Star Wars Roleplaying products. In the Star Wars Legends continuity, the Lambda sector was introduced in Wanted by Cracken, a 1993 supplement to Star Wars: The Roleplaying Game published by West End Games. It was later first visually depicted in The Star Wars Planets Collection, a 1994 supplement authored by Bill Smith for Star Wars: The Roleplaying Game published by West End Games.
- Rise of the Separatists
- Collapse of the Republic