- Role: Heavy Cruiser 
- Origin: Centauri Republic
- Status: in service as of 2281 
- Primary User: Centauri starfleet
- Number Built: >9 
- L x W x H: about a mile in length 
- Heavy Particle-Pulse Cannon x 8 
- Particle-Pulse Cannon x 6 
- Mass Driver x 1 (Optional) 
- FTL via hyperspace jump engines
- Sentri-class Fighters  
- Aerospace Shuttles
Known Named Ships
- The Primus was designed by John Teska. 
- Arguably a “battleship” class but also arguably not.
- Sleeping in Light.
- Four mass driver-equipped Primuses were directly seen bombarding Narn. I would argue that the reflection of the two Primuses in Londo Mollari’s window could only come from two additional Primuses, for a total of six that assaulted Narn. Two Primuses were destroyed in separate battles with Narn cruisers in And Now For a Word and in The Fall of Night. Also, at least one unarmed, VIP-transport variant of the Primus-class was seen during the series.
- Conjecture, but this would be consistent with the other flagship classes of the “Younger Races.”
- The Fall of Night. Note, the weapons sfx for these turrets are the same as for the slightly smaller, more forward turrets.
- And Now For a Word and in The Fall of Night. And Now For a Word also shows anti-ship pulse weapons being fired from the bottom of a Primus‘ hanger bay.
- In the Long Twilight Struggle.
- Seems probable, considering the Primus‘ large hanger bay doors and since all the capital ships of the major B5 powers carried fightercraft… with the exception of the Vorlons.
- The Official Guide to Babylon 5 CD-ROM from 1997 has been disregarded, here, there, and everywhere.
- B5 Scrolls.