From Bravo Fleet Infobase
- The Federation-Cardassian Treaty, primarily negotiated by Admiral Alynna Nechayev, formally ends the Federation-Cardassian War, following the cessation of hostilities three years earlier with the Federation-Cardassian Armistice of 2367, and creates the Demilitarized Zone between Federation and Cardassian space.
- A subspace rift develops in the Hekaras Corridor due to excessive warp speed travel. All Starfleet ships are ordered to not go beyond Warp 5 until a solution is found.
- The Dominion conquers the T-Rogorans.
- The Federation makes first contact with the Dominion when Jem'Hadar forces pass through the Bajoran wormhole, attacking several Alpha Quadrat outposts, taking several officers hostage and attempting to plant a spy within the Federation. While the incursion fails, it makes the start to the Dominion Cold War.
- First contact between the Romulan Empire and the C'hakilian Empire.
- Non-aggression signed between the C'hakilian Empire and the Krazzle Empire following a hundred years of minor border skirmishes between the two powers.
- The USS Voyager is assumed to be lost with all hands while on a mission in the Badlands.
- Late in the year, the Cardassian Obsidian Order and the Romulan Tal Shiar attempt a preemptive joint strike against the Dominion in the Battle of the Omarian Nebula. The battle is the first major engagement with the Dominion, and it ends disastrously for the Cardassian/Romulan task force.
- Portal discovered by Starfleet linking the Alpha Quadrant to the Raeyan Sector.
- Reports leak out of the Cardassian Union that its military government has been overthrown by a popular uprising and replaced by the civilian Detapa Council.
- New technology is issued to starships, effectively cancelling the Warp 5 Speed Limit
- The Dominion replaces Martok, an influential general in the Klingon Defense Force, with a changeling, who calls for a massive invasion of Cardassian space, starting the Klingon-Cardassian War in an attempt to further weaken resistance among Alpha and Beta Quadrant powers.
- The Federation-Klingon War breaks out after the Klingons withdraw from the Khitomer Accords and following their increasingly aggressive stance against all major powers in the region.
- At the start of the year, a cease-fire is reached between the Federation and the Klingon Empire, apparently ending the Federation-Klingon War however, a few weeks later, this cease fire is broken when Klingon troops attack Ajilon Prime. Hostilities only conclude after Chancellor Gowron agrees to reinstate the Khitomer Accords.
- Early in the year, Starfleet engages the Borg Collective in the Battle of Sector 001.
- Starfleet approves the reformation of the Fourth Fleet, initially focused on the Raeyan Sector.
- In the middle of the year, the Cardassian Union enters into negotiations with the Dominion. Subsequently, a Dominion fleet enters Cardassian space and inflicts heavy casualties on the Klingon Defense Force, ending the Klingon-Cardassian War and ensuring Cardassian allegiance. All territory lost during the war is returned to the Cardassian Union, while the Klingon Empire is severely damaged from the encounter.
- In August, the First Battle of Union occurs between the Fourth Fleet's Task Force 38 and a sole ship from the Klingon Defense Force.
- The Romulan Star Empire signs a non-aggression pact with the Dominion.
- As the year draws to a close, the Dominion War begins when a large Dominion fleet is dispatched through the wormhole and captures Deep Space 9.
- The Fourth Fleet transfers primary operations to the Alpha Quadrant to support the war effort, immediately engaging in several offensive operations against Dominion holdings in the quadrant.
- Deep Space 9 is retaken by a Federation fleet including elements from the Fourth Fleet.
- First contact between the Krazzle Empire and the Federation.
- The Federation is devastated by the Battle of Betazed, when the Dominion launches a surprise assault that successfully captures the planet.
- The non-aggression pact between the Romulan Star Empire and the Dominion is forfeit when the Romulan Star Navy declares war and strikes at fifteen bases along the Cardassian border.
- Late in the year, the Federation, Klingons and Romulans ("Federation Alliance") launch their first major offensive against the Dominion with the First Battle of Chin'toka. While ultimately successful, the losses incurred prevent further advances into Cardassian space.
- The Klingon Defense Force suffers a sordid defeat by the Dominion when it unanimously attacks the Cardassian/Dominion shipyards around Monac IV.
- Section 31 unleashes a morphogenic virus that infects the Dominion Founders.
- The Dominion forms an alliance with the Breen Confederacy and pushes forward with a successful offensive:
- The Breen launch a surprise attack against Starfleet Headquarters.
- The Dominion launch a counterattack against the Federation Alliance in the Second Battle of Chin'toka. Buffeted by a previously unknown Breen energy dampening weapon, the Federation Alliance suffers a 99.6% casualty rate during the battle.
- The Fourth Fleet suffers heavy losses in the Badlands in a successful attempt to retake Draconia from the Dominion.
- The Federation Alliance defeats the Dominion in the final Battle of Cardassia, ending the Dominion War.
- The Fourth Fleet adjusts to peacetime, restructuring into ten task forces spread across the Alpha, Beta and Gamma Quadrants.
- First contact is made between the Federation and the C'hakilian Empire after an engagement that leads to the destruction of a Starfleet vessel.
- The Dominion pulls back behind its core borders and enters a period of seclusion.
- The USS Voyager first discovered the Gradin Belt when it passed through and destroyed a subspace vortex controlled by the Malon Cooperative. For the next fifteen months, it travelled through the Gradin Belt and made first contact with dozens of species including, most notably, the Devore Imperium, the Hierarchy, the Turei Alliance and the Vaadwaur.
- Starfleet discovers the Union Gateway, an Iconian Gateway linking the Union system in the Raeyan Sector to the F'hoca Gateway a region of the Delta Quadrant now known as the Old Theatre.
- The Fourth Fleet assigns Task Force 38 to start charting the Delta Quadrant through the Union-F'hoca portal.
- Worf, son of Mogh, names Martok as Chancellor of the Klingon Empire, and relations between the Klingons and the Federation take a turn for the better.
- Diplomatic relations are established between the Federation and the Trigati Republic.
- Hostilities begin to heat up between the Federation and the C'hakilian Empire.
- Bajor officially joins the Federation.
- The USS Voyager returns to the Alpha Quadrant after destroying one of six Borg transwarp hubs, dealing a significant blow to the Borg Collective.
- C'hakilian Empire captures Avalon Fleet Yards, the Raeyan System and a number of other Federation outposts in the Raeyan Sector, beginning the C'hakilian War. At the invitation of the Klingon Empire, Federation personnel bivouac to the Klach d'Kel Brakt system.
- Task Force 21, the Fourth Fleet's intelligence wing, launches successful attacks behind C'hakilian lines to disrupt supply lines.
- Near the end of the year, a massive Federation-Klingon fleet successfully retakes C'hakilian-held assets in the Raeyan Sector while simultaneously fending off a counterattack on Klach d'Kel Brakt. The C'hakilian Armistice Treaty is signed between the Federation-Klingon alliance and the C'hakilian Empire to end the C'hakilian War.
- First contact is made between the Federation and the Ratarian Republic when the republic responds to a distress signal from a Federation vessel and orders it out of Ratarian space.
- Shinzon leads a nearly successful coup d'état of the Romulan Empire.
- Deep Space 6 along the Romulan Neutral Zone becomes the headquarters of Task Force 93 following the Shinzon incident.
- The Klingon Empire begins an in-depth exchange program with the Fourth Fleet.
- The Gorn Hegemony attacks and occupies Cestus and the surrounding sector, leading to the Gorn Crisis and a formal declaration of war by the Federation.
- A combined force drawn from Task Force 93, Task Force 72 and Task Force 63 drives the Gorn back and penetrates deep into Gorn territory, the war drawing to a conclusion when the Hegemony sues for peace after the fleet reaches the Gorn homeworld.