This is a list of events that occurred in 2259. Unless otherwise noted, the timing and sequence of events are taken from "The Babylon 5 Historical Database," published in Across Time and Space: The Chronologies of Babylon 5.
- Ambassador Delenn enters a chrysalis.
- Earth Alliance President Luis Santiago dies when Earthforce One explodes over Io. Vice President William Morgan Clark is sworn is as President aboard Earthforce Two.
- G'Kar departs Babylon 5 to investigate the destruction of the Narn outpost in Quadrant 37
- The Trigati is sighted in Earth Alliance space. It will be seen again over the next several days.
- Sinclair arrives at Earth 
- An Earth Alliance transport is hijacked, and the EAS Agamemnon, commanded by Captain John Sheridan comes to their aid.
- G'Kar returns to Babylon 5 to warn about the Shadows.
- A Narn heavy cruiser is destroyed at Z'ha'dum.
- Michael Garibaldi awakens from his coma.
- Delenn emerges from the chrysalis, transformed into a Minbari-human hybrid.
- Garibaldi's Aide is arrested for shooting Garibaldi. He is quickly implicated in a plot to assassinate President Santiago.
- Ambassador Sinclair leaves Earth for Minbar aboard the cruiser Solaris. 
- Under orders of President Clark, Garibaldi's aide is transported back to Earth. En route, the transport carrying him vanishes, along with all the proof collected by station personnel.
- Lord Refa meets with Ambassador Mollari, thanking him for dealing with Quadrant 37 on December 31st.
- Just as Refa leaves the station, a group of techno-mages, led by Elric, arrive and begin meeting in Downbelow. Mollari tries to wrangle an endorsement out them to cement his new position in the Republic.
- The Drazi begin fighting with one another, based on those wearing green and purple sashes. As part of her first diplomatic duty, Commander Ivanova is assigned by Sheridan to find a solution to the conflict.
- The Drazi conflict comes to an end when Ivanova becomes "Green Leader." She stops the fighting by taking all of the Green Drazi and having their sashes dyed purple.
- The EAS Cortez is rescued from hyperspace and returns to Babylon 5. Lt. Ray Galus dies in a collision with a Shadow Vessel. Late that night, Lt. Warren Keffer returns after being lost helping the Cortez make it back safe, having followed the ship back through space..
- Michael Garibaldi enjoys Bagna Cauda with Dr. Stephen Franklin. Warren Keffer is made wing leader of Zeta Squadron.
- The EAS Cerberus is destroyed by a Shadow Hybrid in the Lanep System. Ensign Matthew Gideon is the only survivor.
- On Mars, Alfred Bester learns that an underground railroad for rogue telepaths is operating through Babylon 5.
- Londo Mollari celebrates his thirtieth anniversary of his Day of Ascension by divorcing two of his three wives. He is nearly killed during the festivities.
- The Sh'lassen Triumvirate appeals to Babylon 5 for assistance with a rebellion. Captain Sheridan is ordered to turn down their request.
- Centauri Emperor Turhan arrives on Babylon 5, intending to seal the rift between his people and the Narn before his death. Shortly into his visit, he collapses and is rushed to the Medlab facility. He gets Dr. Franklin to pass along his message of apology to G'Kar.
- Londo Mollari asks Morden to get his "associates" to destroy the Narn base in Quadrant 14.
- The Narn reinforcements arrive just as a Centauri cruiser comes out of hyperspace to check on the situation. The destruction of the base is blamed on the Centauri.
- Emperor Turhan dies of heart failure. The Narn-Centauri War begins. Jeffrey Sinclair informs Michael Garibaldi about the Rangers.
- A week after the Sh'lassen Triumvirate request for help with a rebellion was turned down, General Richard Franklin arrives on Babylon 5 with 25,000 Earthforce Marines on a secret mission to Akdor to assist the Triumvirate.
- Babylon 5 receives a major upgrade to its Defense Grid.
- Franklin's mission is made public as he departs the station.
- Operation Sudden Death commences.
- Ta'Lon and several others are abducted by the Streib.
- Captain Sheridan is abducted by the Streib. Delenn is stripped of her title and position on the Grey Council.
- General Hague visits Babylon 5. Kosh gives Sheridan a vision before he and Ta'Lon are rescued by the EAS Agamemnon and fighters from Babylon 5.
- Sheridan informs Susan Ivanova, Michael Garibaldi, and Stephen Franklin about his part in a conspiracy to expose President Morgan Clark. All three join him.
- While Sheridan, Delenn and Ivanova are away from the station during the Streib situation, Catherine Sakai returns to Babylon 5 after spending several months out on the Rim and is surprised to find that Sinclair is no longer on the station. She eventually finds Michael Garibaldi who provides her with travel documents, left for her by Delenn so she can come to Minbar and reunite with Sinclair. 
- Dr. Everett Jacobs arrives on Babylon 5, fleeing agents of President Morgan Clark who arrive on the station soon afterwards.
- Dr. Jacobs leaves the station safely after some help from Ambassador Kosh.
- Week 4
- Captain Sheridan learns Morden is still alive and has him detained for questioning. Ambassadors Delenn and Kosh explain to Sheridan the history of the First Shadow War and the return of the Shadows, as well as what happened to the Icarus on Z'ha'dum.
- The Ministry of Peace establishes the Nightwatch, opening one chapter on Babylon 5 (Zack Allan joins).
- Lyta Alexander arrives on Babylon 5 warning of a traitor on the station: Psi Corps had implanted a "sleeper personality" on someone aboard.
- Susan Ivanova confesses to Captain Sheridan that she is a latent telepath. Talia Winters is proven to have the hidden sleeper personality. She effectively dies when the Control personality asserts itself.
- Warleader G'Sten visits G'Kar on Babylon 5. Londo Mollari confers with Antono Refa on Centauri Prime about how to end the Narn-Centauri War.
- Battle of Gorash 7: a decisive defeat for the Narn Regime at the hands of a Shadow fleet.
- A Centauri fleet commences orbital bombardment of Narn with mass drivers.
- After four days of bombardment of Narn, the Narn Regime surrenders to the Centauri Republic. G'Kar requests sanctuary on Babylon 5.
- Ambassador Kosh reveals himself to the inhabitants of Babylon 5 when he rescues Captain John Sheridan.
- Lt. Warren Keffer is killed by the Shadows in hyperspace.
- Images from Keffer's Starfury camera are broadcast on ISN. The broadcast is pulled off the air and the footage is turned over to EarthForce Special Intelligence Research Division for study 
|Before the Third Age:||20th Century and earlier - 21st Century - 22nd Century - 2200s - 2210s - 2220s - 2230s - 2240s|
|2250s:||2250 - 2251 - 2252 - 2253 - 2254 - 2255 - 2256 - 2257 - 2258 - 2259|
|2260s:||2260 - 2261 - 2262 - 2263 - 2264 - 2265 - 2266 - 2267 - 2268 - 2269|
|2270s onwards:||2270s - 2280s - 2290s - 2300s and beyond|