The Narn have a bloody history of war with Centauri; the two people hate each other so intensely that the very site of the other race will cause aggressive activity on both sides' parts. After being occupied for decades, the Narn drove the Centauri from their world. But in 2259, war broke out between the two races, and it would not go well for the Narn.
In late 2259, the Narn homeworld was occupied by the Centauri for the 2nd time in history. For over a year, the Centauri held Narn under its boot, enslaving its people and executing many of them. But after the death of Cartagia, the Centauri have left Narn, presumably for good. The people of the planet can now rejoice and begin rebuilding their planet and their fleet.
"Here is the information we have concerning G'Kar:"
"The Narn space forces are essentially non-existent right now, but we still have many of their files still in the database."