Pre-22nd Century
- See also Pre-22nd Century.
In the time before the 22nd century, many ancient civilizations arose and declined. Iconians, Preservers and the Tkon Empire are some of the oldest known races of the Milky Way. History also paved the way for space exploration and conquests on several notable Alpha and Beta Quadrant worlds, among them Vulcan, Romulus, Qo'noS and Earth.
 22nd Century
- See also 22nd Century.
 23rd Century
- See also 23rd Century.
The 23rd Century marked a time of unstable politics and constant power struggles in the Alpha and Beta Quadrants. However, seeds were sown that lead to a period of relative peace in the following century.
 24th Century
- See also 24th Century.
The beginning of the 24th Century is marked by a relative peaceful time for the Federation. However, several large-scale conflicts and catastrophes drastically changed the Alpha and Beta Quadrants since the 2360s. This time also marked the beginning of the exploration of the Delta and Gamma Quadrants by Starfleet.
 25th Century
- See also 25th Century.
So far the 25th Century is defined mostly by war and unrest in the Alpha and Beta Quadrants. While at war with each other, the Federation and the Klingon Empire also face threats by the Borg, the Undine, the Iconians, the Dominion and an unstable Romulan Star Empire, among many others.
- The current in-game year is still 2409, even though stardates correspond to the year 2412 by now. There might be a change of time sometime in the future, but that will not correspond to stardates or real life time progression.
- The timeline articles concentrate on events that are relevant to Star Trek Online. More detailed information about general Star Trek lore can be found at Memory Alpha.
- Information that is not derived directly from in-game sources (such as system descriptions or NPCs) mostly comes from the novel The Needs of the Many and the official Star Trek Online website's The Path to 2409
Timeline of Star Trek Online
2390 • 2391 • 2392 • 2393 • 2394 • 2395 • 2396 • 2397 • 2398 • 2399
2400 • 2401 • 2402 • 2403 • 2404 • 2405 • 2406 • 2407 • 2408 • 2409