From Bravo Fleet Infobase
- The Starfleet Corps of Engineers begins a project that will culminate seven years later with the Federation transwarp network.
- A rogue element of the C'hakilian military attempts an assault agaisnt the Federation in the Raeyan Sector with secret support from the Romulan Tal Shiar, starting the C'hakilian Armistice Crisis.
- Task Force 21 retakes Starbase 611 lost at the beginning of the C'hakilian Armistice Crisis.
- The rogue C'hakilian fleet is defeated in the Lantra system, lacking support from the C'hakilian Emperor.
- Cardassian Central Command is said to have rebuilt most of its former self.
- The Triangle Region is placed under the purview of Task Force 86.
- The Tripartite Treaty is signed between the Federation, the Klingon Empire and the Romulan Empire, granting unfettered access to the Union Gateway for all three powers.
- The C'hakilian Empire becomes afflicted with a plague, issuing an apology to the Federation and withdrawing from the interstellar scene.
- With an expansion of operations in the Omega Antares Sector, several forays into space beyond the Federation borders are repulsed by the Ratarian Republic and concerns begin to amount about the unknown species. The Romulan Star Empire, also concerned with the developments, is granted a garrison on Deep Space 13 and co-colonization rights to the Omega Antares Colony.
- Starfleet establishes a base in the Gavarian Frontier and Task Force 47 begins operations in the region.
- The Borg Collective attacks Starfleet's presence in the Delta Quadrant, taking Starbase 900 and forcing Task Force 38 back to withdraw back through the F'hoca Gateway. For reasons unknown, however, they do not pursue Starfleet back through the Union Gateway.
- Romulan Neh'Rihar Fleet Yards were attacked and seized by the Tholian Assembly before being forced back; the Romulan Star Navy choses not to pursue war with the Tholians though, instead preferring to focus on other fronts.
- In the middle of the year, Task Force 38 launches a ship back through the Union Gateway and discovers that the Borg Collective has withdrawn from the F'hoca Gateway. Operations renew carefully within the Old Theatre.
- The Detepa Council of the Cardassian Union formally requests that all Federation and allied vessels depart Cardassian space in order to allow the Cardassians to fully support themselves.
- In December, the Omega Crisis of 2383 begins following the discovery of an omega molecule in the Old Theatre headed directly for the F'hoca Gateway.
- Omega Crisis of 2383 ends with the Second Battle of Union and the destruction of the F'hoca Gateway in the Delta Quadrant, completely closing off access to the Old Theatre.
- The Treaty of Union nullifies most of the rights granted to the Klingon Empire in 2381 by the Tripartite Treaty in response for their actions during the Omega Crisis of 2383.
- It is discovered that the Union Gateway, which lost its pairing following the destruction of the F'hoca Gateway, has acquired a new connection to the Solaria Gateway. This grants the Federation access to a new region of the Delta Quadrant now known as the Round Table and beings a new era of exploration for Task Force 38.
- The Krazzle Empire becomes the Krazzle Republic, signs the Ge'Ovan Charter with the Federation and moves into a period of inward focus.
- The Cardassian Union begins to flex its muscles following a long period of rebuilding after the Dominion War.
- Increasing hostilities from the Cardassians expands Task Force 47's mandate within the Gavarian Frontier.
- Romulan sentiment towards the Federation takes a turn for the worse. Task Force 21 is merged into Task Force 93 to bolster Starfleet's presence along the Romulan Neutral Zone.
- After a Borg sphere is encountered near the Omega Antares Sector, and following continued difficulties with the Ratarian Republic, Starfleet withdraws from the region to deal with issues closer to home such as increasing pressure from the Cardassians, Romulans and others.
- In September, a terrorist organization, acting against the Federation's new alliance with the Raydeen Republic, sabotaged the Bajoran Wormhole, prompting it to collapse. The Dominion seize the opportunity to whittle away at the stranded Federation forces.
- In response to Starfleet's build up along the Romulan Neutral Zone, the Romulan Star Empire orders its citizens off of Qualor III, a joint Federation-Romulan colony. Romulan relations take a turn for the worse.
- Inexplicably, the Valoris Nebula begins to rotate, moving Federation worlds into Breen space and vice versa. This leads to the Breen Crisis and most notably the Battle of Garen Epok.
- In April, a scientific experiment gone wrong in the Gamma Quadrant succeeds in reopening the Bajoran wormhole.
- Similar to the withdrawal from the Omega Antares Sector a year earlier, Starfleet closes down primary operations in the Raeyan Sector as its importance wanes. This includes mothballing and destroying many assets, as well as reallocating resources from Task Force 58 to bolster support along the Romulan Neutral Zone, the Gavarian Frontier and the borders with the Cardassian Union and Breen Confederacy.
- A Cardassian group calling itself the Order of 12 destroys several facilities in the Gavarian Corridor, as well as killing a number of Starfleet personnel, including flag officers.
- Rear Admiral Kara Thrace and Admiral Tolak tr'Servek negotiate an amendment to the Treaty of Algeron that reduces the size of the Romulan Neutral Zone and corrects the course of relations between the two powers in a more positive direction.
- On April 13, the Hobus star goes hypernova, destroying Romulus and Remus and sending the Romulan Star Empire into turmoil. Task Force 93 assists with evacuation efforts.
- The Romulan Empire moves its seat of power to Rator.
- Task Force 93 becomes completely focused on the aftermath of Hobus in the spring and summer, providing support and relief efforts to the Romulan Empire.
- The Klingon Defense Force and raiders from the Triangle Region launch a number of incursions against Romulan space.
- On August 17, the Algorab Summit is called to address concerns from borderlands governors regarding the Navy's struggles to provide them adequate support post-Hobus. During the proceedings, Starfleet Intelligence is implicated in the assassination of a Romulan senator, shattering Federation-Romulan relations.
- On September 20, the Treaty of Nelvana is signed, restoring the original provisions of the 2311 Treaty of Algeron, closing the Romulan borders to the Federation, and ceding the Raeyan Transit Corridor to the Federation.
- Task Force 93 expands to include the Raeyan Sector, the Raeyan Transit Corridor and the Triangle Region, in addition to its former positions along the Romulan Neutral Zone.
- On October 15, the Gavarian Armistice Agreement is signed between the Federation and the Cardassian Union, limiting Starfleet operations within the corridor to Task Force 47 alone and Cardassian operations to the 7th Order.
- In November, Starfleet announces plans to quell the singularity within the Valoris Nebula. These plans are expected to be executed in mid-2388.
- In January, Task Force 72’s mandate is expanded, allowing it to stretch into the Inconnu Expanse.
- On February 2, the Cardassian Seventh Order attacked a Romulan convoy leaving the Quillian system, starting the Cardassian-Romulan War.
- On March 1, Task Force 47 is disbanded with elements dissolved into both Task Force 72 and Task Force 93. Starfleet withdraws from the Gavarian Corridor.
- In May, a group known as The Consortium took control of Deep Space 11, the Bajoran Wormhole and Task Force 9 as an attempt to disrupt Starfleet’s activity in the Gamma Quadrant. Starfleet assets unaffected by the Consortium regroup at Starbase Unity.
- In June, the Borg attack the Delta Exploratory Initiative in what becomes known as the Battle of the Round Table. Task Force 38 suffers heavy casualties, including the destruction of Starbase 900, and is forced to destroy the transwarp gateway connecting The Round Table to the Alpha Quadrant in order to protect the Federation. This leads to the complete isolation of Task Force 38 in the Delta Quadrant.
- On July 2, the Gorn Hegemony launched a surprise invasion of the Cestus and Canterra systems. Starfleet’s Xavier Fleet Yards were also attacked during this time, along with other Federation assets, preventing the Federation from responding to the Gorn attack.
- In July, Task Force 9 enters into an agreement with the Dominion. In exchange for helping Starfleet rid themselves of The Consortium, the Dominion will maintain a presence at Deep Space 11.
- In August, a joint Starfleet-Dominion Task Force is able to retake Deep Space 11 and the Bajoran wormhole. The Consortium flee into the shadows.
- In August, Task Force 38 discovers the Epatha Gateway, a cyclical wormhole that connects The Round Table to the Gradin Belt every 9 days. Task Force 38 expands its area of operations to include the Gradin Belt and begins research on the Epatha Gateway, hoping to use its wandering nature to find a way home.
- On October 10, the Second and Fifth Orders of the Cardassian Guard breached the borders of the Breen Confederacy and retook four systems, including Dozaria, Portas V and Sentek.
- On November 25, Task Force 38 discovers that the Epatha Gateway connects to the Raeyan Sector for 15 minutes every 45 days. It sends word of this discovery to the Federation during the window on this day, prompting Starfleet to mount a relief effort to re-enforce Task Force 38 in January 2389.
- In December, the Sovereignty of Kahless rises to power within the Klingon Empire, nearly forcing the Empire into Civil War.
- In January, the Cardassian Union, Romulan Star Empire, and the Federation signed the Gavarian Exploration Agreement, effectively ending the Cardassian-Romulan War. This agreement also allows the Federation to return to exploring the Gavarian Corridor once again.
- In March, the Breen Confederacy, Tzenkethi Coalition, Talarian Empire, and the Ravagers band together and form the Alrakis Pact. One of their first objectives is to remove the Federation from the Inconnu Expanse.