The Cassandran Worlds were a region of loosely-allied planets located within the galaxy's northern quadrant in the New Territories of the Outer Rim. The Cassandran Worlds were established roughly a century before the fall of the Galactic Republic by Cassander Tadrin, a bored Esselian businessman who was tired of the self-satisfaction lifestyle of the Core Worlds. After funding a series of missions into the galaxy to discover new planets, he led tens of thousands of his loyal employees and their families to settle the new planets. The Cassandran Worlds consisted of over a hundred planets, including Cassander, New Bakstre, Minashee, Garqi, Forsen, Biitu, Isiring and Monhudle. Jedi Master Sifo-Dyas hailed from the region.
Shortly before the Battle of Yavin, the Galactic Empire annexed the Cassandran Worlds. They split the region into three distinct subsectors known as the Cassandran sectors;—Cassander, Tadrin, and Tendrannan.