The Briar Patch is the colloquial name for a region of space in Sector 441, bordering the territories of the United Federation of Planets and the Klingon and Romulan Star Empires. The Patch, as it is often called, consists of gaseous anomalies, metaphasic radiation, supernova remnants, and other dangerous space detritus, making warp travel extremely hazardous and next-to-impossible. Known to the Klingons as Klach D'Kel Brakt, its informal name was coined by the human scientist Arik Soong, in reference to a children's literature series from Earth. The Patch is also the location of several habitable worlds, including the Ba'ku planet. (Star Trek: Insurrection; ENT: "The Augments")
In 2271, Klingons under the command of Dahar Master Kor won a decisive victory over the Romulan Star Empire during the Battle of Klach D'Kel Brakt. Over a century later, in 2375, the USS Enterprise engaged Son'a forces in the Battle of the Briar Patch. (DS9: "Blood Oath"; Star Trek: Insurrection)
- Note that when the Briar Patch first appeared in Star Trek: Insurrection, it was intimated, though not explicitly stated, to be in the Alpha Quadrant, not far from the Dominion War theatre of operations as the Son'a were secondary participants in that conflict. It was only several years later that Star Trek: Enterprise would place the Briar Patch in the Beta Quadrant near Klingon territory and connect it with Klach D'Kel Brakt, a reference from an earlier Star Trek: Deep Space Nine episode. As such, fanon projects originating before the Enterprise episode often ignore that development in favor of their own preexisting continuity.
Following the Ba'ku incident in 2375, Starfleet established Outpost 40 in the Briar Patch, also known as the Ti'krit Expanse, and eventually augmented that facility by building Deep Space 12 in orbit of Ba'ku. During the late 2370s and into the 2380s, the Tholian Assembly would show great interest in the Briar Patch, often coming into conflict with Starfleet and its allies. The Cardassian Union, the Son'a, the Tzenkethi and the Breen also entered into conflicts over the Briar Patch during this period.
Due to the Briar Patch's unique composition of metreon clouds and metaphasic radiation, travel at normal warp speeds is impossible in the region. Modifications can be made to impulse drives to allow starships to travel above the one-third impulse usually required. Limited to sublight speeds, attempts to explore deeper into the Patch proved fruitless, until the Federation learned of naturally-occurring subspace currents that would allow warp travel within the Patch. The Tholians also used these currents.
At one point, the Ti'krit Expanse was home to an advanced ancient civilization, the creators of the tetrahedrons which were eventually discovered throughout the Patch and the nearby McAllister Nebula. The Briar Patch is also the home of the Grey Confederacy, the Tren'La and a number of cosmozoan species.
In 2381, around stardate 58532.1, Starfleet discovered that the Grey had built a massive dyson sphere around their home star. The sphere was composed of millions of tetrahedrons. (Star Trek: Hidden Frontier, Star Trek: The Helena Chronicles, Star Trek: Odyssey)
After the destruction of the dyson sphere in 2383, the Briar Patch dissolved and the region reverted to normal space for the first time in centuries. While Starfleet and the humanoid inhabitants of the Patch had cause for celebration, this turn of events displaced numerous cozmozoan lifeforms indigenous to the area. Following the dissolution of the Patch, Starfleet established the Regeneration Shipyards at Ba'ku. (HF: "Its Hour Come Round At Last"; THC: "Sanctuary"; ODY: "Iliad")
The Briar Patch is approximately 400 lightyears from Earth in the Alpha Quadrant wedged between the borders of the Ferengi Alliance and the Breen Confederacy. It is an irregularly shaped nebular region containing many pockets of metaphasic radiation, supernova remnants, subspace sandbars, and other serious hazards to navigation. There are few safe routes through the region to the other side. One such route exists between Starbase 732 and Starbase 901 in the New Canada system.
There are several inhabited planets inside the Patch, including Ba'ku, Gaia, and Oo-oo-ah. Iconian artifacts have been discovered, and there is evidence of other, much older civilizations present. Son'a, Nausicaans, and Mulluran pirates used the Patch as a hiding place.
Several large convoys of supply ships and one civilian cruise liner with over 1000 on board have mysteriously disappeared in the Briar Patch and the Trans-Briar Patch sectors. Pirate activity was long suspected, but in reality it was an unknown alien race called the Jelly Brains by some that was responsible.
The Briar Patch became a strategically important sector of space following the Dominion invasion of Betazed in 2374. The USS Lambda Paz, as part of the Seventh Fleet, began operating out of Starbase G-6, which was near the Patch.
The Dominion successfully lured the Lambda Paz to the edge of the Patch with a fake distress call from a Vulcan freighter seized by the Sindareen. Once the ship was seized, the combined crew of Cardassian and Jem'Hadar soldiers took it further into the Patch while repairs were made. ("The Tides of War, Parts 1 and 2")
Because Sindareen pirate Tor Vot was promised access to a new source of wealth in return for his services as a Temporal Cold War proxy agent, he refused to accept being relegated to using the stolen freighter, to give the distress call a measure of credibility, after failing to deliver Limis Vircona to Gul Enic Hadar. He was determined to complete his mission to turn over Limis to a cohort of Future Guy, even threatening to open fire on the Dominion-held Lambda Paz. When Limis returned to the 24th century via the Orb of Time and Tor Vot's temporal communication device, she offered to let Tor Vot take refuge in the Patch if she was returned to her ship. ("The Tides of War, Part 2")
Because of its proximity to the Patch, a diplomatic conference between the Federation and Bajor was relocated to Starbase G-6 from Bajor because of rising civil unrest following the disappearance of the Bajoran wormhole. ("Faces in the Crowd")