Assassin's Creed uses the name “the Isu” for the ancient civilization that existed before humanity. The Isu are also called the Precursors in the series' lore.
They were an advanced species responsible for creating powerful artifacts, including Pieces of Eden. Their civilization predates recorded human history, and many games reveal their influence through temples, symbols, genetic memories, and recovered technology.
The Isu are connected to the franchise's central conflict because humans were created and controlled by them before eventually rebelling. Major Isu figures include Minerva, Juno, and Jupiter, although different games reveal their stories in different ways. They are sometimes incorrectly called “the First Civilization,” which is a descriptive label used in the series; “the Isu” is the specific name most associated with the people themselves.