Mike Rouse-Deane

Revision History
Revision 1 8 March 2002

Approved by Unknown

Table of Contents





Height (Average)

6' - 7'

Weight (Average)




Entry Type



"The Loss" (TNG), "Penumbra" (DS9), "Til Death Do Us Part" (DS9), "Strange Bedfellows" (DS9), "The Changing Face of Evil" (DS9), "When It Rains..." (DS9), "Tacking Into The Wind" (DS9), , "The Dogs Of War" (DS9), "What You Leave Behind" (DS9)

Found in Starfleet



A powerful and mysterious Alpha Quadrant species, the Breen are one of the very few major species who have evolved on a non-class M world. The Breen homeworld has an average temperature of approximately -53 C, a record low for any inhabited planet. They have evolved with a unique physiology in order to cope with this ultra-cold environment; although they breathe a fairly standard oxygen-nitrogen atmosphere at close to normal pressure, the Breen have no blood or other liquid circulatory system. Instead, their body is permeated by millions of tiny hollow tubules which are open to the skin. These allow oxygen to be carried directly into the body; once there it is absorbed directly through the skin to be used by the internal organs. A similar process carries the waste gasses back out again. The Breen reproductive cycle is also unusual, in that they commonly produce offspring at a very early age.

Normal Breen body temperature is -38 C; exposure to temperatures above -13 C will kill a Breen within minutes. Given that most known major spacefaring species live on class M planets with an average temperature far above that of Breen, the Breen have had to develop environmental suits of great capability and reliability in order to co-exist with others. Given their nature, it is understandable that the Breen have become one of the Alpha Quadrants leading experts at creating and maintaining extremely cold environments. They are acknowledged experts on cold storage of chemical compounds.

Given the environmental difficulties, casual visits to Breen worlds by non-Breen are virtually impossible. The Breen strongly discourage visitors, and all those who do visit Breen worlds are confined to purpose-designed encampments. Combined with the fact that the Breen habitually design environmental suits which hide their faces from view, this has given them their air of mystery. This has been further enhanced by the fact that some empathic species, most notably Betazoids, are unable to detect the thoughts or emotions of the Breen. Much of Breen is known to be a frozen wasteland, and it is widely thought that the Breen have deliberately avoided large surface developments for cultural reasons.

Nevertheless, much has been discovered about the Breen over the years. They have developed organic technology to the point where they routinely use biological spacecraft. Some of these are fitted with cloaking devices, a technology the Breen apparently invented independently of the Romulans and Klingons. They use disruptor type weaponry rather than the phaser technology used by the Federation. They are also the manufacturers of the CRM-114... an extremely powerful portable hand cannon designed to destroy moving targets and surface emplacements. The Breen use disrupters as their primary weapons. They are classified as type 3 and discharge blue pulses.


The Breen have something of an aggressive history. They are politically non-aligned, and have been known to attack Federation vessels. The Breen utilize privateers, and one group of them attacked the Bajoran Colony of Free Haven in 2372. The Breen have outposts near the Black Cluster, and have settlements at Portas V near the Demilitarized Zone. A Breen of unknown identity was replaced by a founder at some unknown date, and the "original" was imprisoned in Internment Camp 371. This Breen gave his life by initiating an escape from the camp in 2373, shortly after Cardassia joined the Dominion. In 2366, two Breen warships attacked the Cardassian ship Ravinok then forced it to crash land on Dozaria where they put the crew and passengers on that ship into a forced labor camp on the surface. There, the survivors of the crash mined dilithium under the watchful eye of Breen guards. The Breen may be known for their low integrity and backstabbing nature, as there is a Romulan saying "Never turn your back to a Breen".

Though normally politically non-aligned, the Breen allied themselves with the Dominion during the later part of the war, in 2375, with the Federation Alliance. The Founders secretly conducted talks with the Breen, promising them nearly the entire Alpha Quadrant, if and when they were to win the war. Among the more notable systems promised to the Breen by the Founders were Romulus and Earth.

The Breen made their presence felt almost immediately when they joined the war by attacking the heart of the Federation, Earth. The attack was meant to make them feel weak and vulnerable. Very few Breen ships survived the attack on Earth. The Breen also figured greatly in the battle for the Chin'toka System. The Breen unleashed a weapon that had not been known to exist, an energy-dampening weapon, which rendered ships powerless, defenseless, and helpless. The battle was a devastating defeat to the Federation Alliance. The only good news they came away from in this battle was that the Klingon ships were not affected by the Breen weapon.

The Klingons alone would hold the Dominion forces to their side of the front line until a countermeasure could be found to the Breen weapon. Thanks to the Cardassian rebels fighting to free their world from the Dominion, a Dominion ship with the Breen weapon newly installed was stolen and returned to the Federation for study. A countermeasure was later developed for the Breen energy-dampening weapon.

A large Federation-Klingon-Romulan fleet entered Cardassian space looking to end the war. During the battle, a turning point was reached when the Cardassians switch sides and began firing on the Jem'Hadar and Breen ships. The Dominion retreated to Cardassia. With their new Cardassian allies, the Federation Alliance pushed onward to Cardassia Prime. After linking with fellow changeling Odo (convincing her to stop the bloodshed), the female Founder agreed to surrender, and the war was over.