The Phu system existed within the regions of space referred to as the Colonies and also the Interior. Its location was identified as grid square J-13 on the Standard Galactic Grid, and it was the home of the world known as Phu. Bardottans hailing from the planet Bardotta at some point established a colony on Phu.
During the Clone Wars, specifically in 22 BBY, a task force belonging to the Galactic Republic and composed of Venator-class Star Destroyers entered the Phu system. Their objective was to locate the Separatists' heavy cruiser named Malevolence. The Malevolence initiated an ambush, obliterating the Star Destroyers before escaping undetected. Some Years afterwards, specifically in 34 ABY, the coordinates of this star system were displayed on a galactic map shown on several screens found on the Star Cruiser Halcyon.
The Phu system initially entered Star Wars canon in the forty-third issue of the magazine Star Wars: Build the Millennium Falcon, which was published by De Agostini around October 28, 2015. The first in-universe depiction of the Phu system took the form of a map that could be viewed in Star Wars: Galactic Starcruiser, an immersive roleplaying experience at Walt Disney World Resort in Florida that became accessible to the public starting on March 1, 2022.
Within the Star Wars Legends continuity, the system was first mentioned via a map in the 2000 reference book titled Inside the Worlds of Star Wars: Episode I, written by Kristin Lund. Its name was later revealed in The Clone Wars: Shakedown, written by Pablo Hidalgo, which was the second installment of the Star Wars: The Clone Wars webcomics series and went live on October 2, 2008.