XENOMORPH TIMELINE
Aliens is a movie released in 1986. Its story takes place in 2179, 37 years after Alien: Romulus (2142) and right before Alien 3 (2179). In the Alien movies timeline, it comes after Alien: Night Shift (around 2164) and before Alien 3 (2179).
No year is given on screen. Ripley has been adrift for 57 years since the loss of the Nostromo, and licensed books such as Alien: River of Pain and Alien: The Weyland-Yutani Report date the events to 2179.
"Aliens," released in 1986 and directed by James Cameron, is the sequel to Ridley Scott's 1979 sci-fi horror film "Alien." Set 57 years after the events of the first film, it follows Ellen Ripley (Sigourney Weaver) as she returns to LV-426, now a terraforming colony, with a team of colonial marines to investigate why contact has been lost. They soon discover that the colonists have been overrun by a horde of deadly Xenomorphs. Lance Henriksen plays the android Bishop.
The story takes place in 2179. Between the two films come "Alien: Isolation" (2137), in which Ripley's daughter Amanda searches for her, and "Alien: Romulus" (2142). In a scene cut from the theatrical version and restored in the Special Edition, Ripley learns that Amanda died while she was adrift. The story continues directly in "Alien 3," set the same year.
Decades after surviving the Nostromo incident, Ellen Ripley is sent out to re-establish contact with a terraforming colony but finds herself battling the Alien Queen and her offspring.
Credits : James Cameron (Director)