Star Trek: 10 Things We Now Know About The Breen

Aside from what they look like and that they also have that one uncle, we've learnt a lot about the Breen already in Star Trek: Discovery's fifth season. In the 24th century, the Breen were a 'Confederacy' that did the odd deal with the Ferengi and then tried to conquer the Alpha Quadrant. By the 32nd century, however, as we found out from President T'Rina in Red Directive, the Breen had formed an 'Imperium'. In the episodes that followed, we learnt that factions within the Imperium were warring with each other for control, posing a very real threat to various Federation member worlds.

In fact, from Erigah, we found out that six Primarchs were at war with each other — a "successional dispute" by "disparate branches of the royal bloodline" following the death of the Breen emperor. Moreover, T'Rina also told us that the Federation had had no "official contact" with the Breen "since before the Burn". The last time the Breen had ventured into Federation space was also a disaster for the latter. "Starfleet was caught flat-footed," according to Admiral Vance, and the Breen had "destroyed an entire city," according to Tilly a little later in the episode.

In Mirrors, Primarch Ruhn confirmed the infighting when he said to nephew L'ak, "Yet while we [the Yod-Thot] campaign for the throne of the Imperium, you consort with lesser beings". In that episode, we also learnt of L'ak's royal status from the insignia on his belt, and that he was struggling to "fit the [regal Breen] mould," having been "demoted to shuttle bay duty" before going on the run.

In the possible (bleak) future of Face the Strange, Commander Rayner, Captain Burnham, and Zora got chatting. There, Federation HQ, and probably most of the Federation too, had been destroyed by the Breen. "They [the Breen] must have been Moll and L'ak's highest bidders," Rayner concludes. Spoilers! Now, get the Krenim chronophage outta there!

From Erigah, we also now know that Commander Rayner's homeworld, Kellerun, was once conquered and controlled by Breen Primarch T'hal (sp?), who used the planet as a "munitions resupply hub," devastating its biosphere, and killing countless many, including all of Rayner's family.