The Cassander subsector emerged as one of the three subsectors that the Galactic Empire established. This occurred following their annexation of the Cassandran Worlds, which are located in the Outer Rim Territories, soon after the Battle of Yavin. The area was then reorganized and became known as the Cassandran Sectors, and it was partitioned into the Cassander subsector, as well as the Tadrin sector, and also the Tendrannan sector. The planet of Cassander was designated as the capital for the entire sector. Besides the Cassander system, the Cassander sector also encompassed other star systems such as the Altunna system, the Forsen system, the Ord Canfre system, in addition to the Peldon Minor system.