: Creator J. Michael Straczynski (JMS) believed the show would be cancelled after the fourth season because its network, PTEN, was folding. To ensure the story was finished, he compressed approximately two seasons of plot into one.
: With the cosmic threat gone, Sheridan turns his attention to President Morgan Clark's totalitarian regime. This campaign culminates in the Battle for Earth, where Clark commits suicide as Sheridan's forces breach the planet's defences.
: The original series finale, "Sleeping in Light," was filmed as the last episode of Season 4. When the show was unexpectedly renewed for Season 5 by TNT, this finale was moved to the end of the next year, and a new Season 4 finale, " The Deconstruction of Falling Stars ," was quickly produced.
: Season 4 ends with the departure of Susan Ivanova (Claudia Christian) and the death of Marcus Cole , who sacrifices his life to save hers using an alien healing device.
The breakneck pace of Season 4 was primarily driven by real-world uncertainty.
: Early in the season (Episode 6, "Into the Fire"), John Sheridan brings the Vorlons and the Shadows into a final confrontation at Coriana VI. He forces them to realize that the "younger races" are done with their proxy war, prompting the ancient races to leave the galaxy forever.
The fourth season of Babylon 5 , titled is widely considered the show's narrative climax. Spanning the year 2261, it resolves the two massive conflicts that had been building since the series began: the war with the Shadows and the liberation of Earth. Narrative Highlights
: On Centauri Prime, Londo Mollari and G'Kar form an unlikely alliance to assassinate the mad Emperor Cartagia . In exchange for G'Kar's help, Londo secures the liberation of the Narn homeworld.