This is a list of events that occurred in 2259:
- 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. President Morgan Clark orders him sent back to Earth.
- The EAS Cortez is rescued from hyperspace and returns to Babylon 5. Late that night, Lt. Warren Keffer returns after being lost helping the Cortez make it back safe.
- Michael Garibaldi enjoys Bagna Cauda with Dr. Stephen Franklin. Warren Keffer is made wing leader of Zeta Squadron.
- The Rangers first come aboard Babylon 5 to plan and coordinate their actions against the Shadows.
- Londo celebrates his 30th anniversary of his Day of Ascension by divorcing two of his three wives (and nearly being killed).
- 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.
- Centauri Emperor Turhan collapses on Babylon 5.
- The Centauri conquer a large Narn colony, Quadrant 37, with the aide of the Shadows.
- The Narn-Centauri War begins with the Narn Regime formally declaring war on the Centauri Republic. Jeffrey Sinclair informs Michael Garibaldi about the Rangers.
- The Sh'lassen Triumvirate appeals to Babylon 5 for assistance with a rebellion. Captain Sheridan is ordered to turn down their request.
- One week after officially turning down the Triumvirate, 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.
- Lyta Alexander escapes the Psi Corps on Mars. She briefly joins the Martian resistance. 
- 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.
- 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.
|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|