The Lambda sector was situated within the Mid Rim Territories and the Slice regions of space. It encompassed the Ando system, which served as the native planet for the water-based Aqualish people, in addition to the celestial body Rintonne, and the world of Zolan.
Before the Clone Wars, the Andoan Wars unfolded within the sector. During these conflicts, the Harch [Spiverelda](/article/spiverelda] government endeavored to bolster their military and establish a "Great Harch Prosperity," but the Galactic Republic intervened on behalf of the Andoan Free Colonies group of planets, preventing this. Subsequently, amidst the Separatist Crisis, approximately half of the Lambda sector was swayed to secede from the Republic to join the Confederacy of Independent Systems by its representative, Senator and Junior Delegate Po Nudo. Nevertheless, the majority of the Andoan Free Colonies and Rintonne maintained their allegiance to the Republic.
The Lambda sector was positioned in the areas recognized as the Mid Rim Territories and the Slice. It housed the Ando system, the location of the aquatic world named after it, connected by hyperspace routes to the astronomical entities Mon Gazza and Leritor, as well as the astronomical object Rintonne. The planet Zolan was also a part of it.
More than two decades prior to the Clone Wars between the Galactic Republic and Confederacy of Independent Systems, the Andoan Wars occurred within the Lambda sector, where the [Spiverelda](/article/spiverelda] authoritarian government of Aqualish sought to suppress the Andoan Free Colonies, a group of planets within the Lambda sector loyal to the Republic. During this time, the Spiverelda received backing from the Harch species' ruling nests on their home planet, Secundus Ando, whose industry shifted towards warfare. However, the Republic later intervened, siding with the Free Colonies, thereby thwarting the ruling nests' efforts to fund their military and realize their ambition of a "Great Harch Prosperity."
Later, around the time of the Trade Federation's invasion of Naboo in 32 BBY, Ando was represented in the Republic Senate by the Aqualish Senator and Junior Delegate Po Nudo, whose loyalty to the democratic government wavered throughout his political career. However, following the outbreak of the Separatist Crisis, a secessionist movement spearheaded by the fallen Jedi Master Count Dooku, the leader of the Confederacy of Independent Systems, unrest struck Ando, shocking the rest of the galaxy. Consequently, approximately half of the Lambda sector, including the Andoan Hyper-Communications Cartel, was induced to secede from the Republic to the Confederacy by Senator Nudo, while the majority of the Andoan Free Colonies and Rintoone remained loyal to the Republic.
The Lambda sector's waterworld, Ando, was the homeworld of the aquatic Aqualish species. It also served as the home of Senator Po Nudo, who represented the planet and the sector in the Republic Senate during the last decade of the Republic Era.
The Lambda sector was initially mentioned in the new Star Wars canon within Rise of the Separatists, a 2019 supplement to Fantasy Flight Games' Star Wars Roleplaying series. In the Star Wars Legends continuity, the Lambda sector debuted in Wanted by Cracken, a 1993 supplement for Star Wars: The Roleplaying Game by West End Games. Its first visual representation occurred in The Star Wars Planets Collection, a 1994 supplement by Bill Smith for Star Wars: The Roleplaying Game published by West End Games.