The B'omar Sovereignty was the political entity of the isolationist and paranoid B'omar race, located in the Delta Quadrant. The Sovereignty claimed to monitor every particle that entered their space, using a sophisticated perimeter grid, and it dealt harshly with all intruders. Positions within the Sovereinty included that of chancellor.
B'omar space contained populated systems and industrial areas, and were trafficked by both military and other craft. It also contained the Agrat-mot Nebula. The B'omar maintained relations with the Nassordin, and were aware of the Borg. (VOY: "The Raven")
In 2374, the Federation starship USS Voyager arived at the B'omar "uninvited and unwelcome". Facing a three-month detour going around B'omar space, Voyager set out to negotiate passage, which the Sovereignty reluctantly granted with the provision that it take a tedious and circuitous route through their territory.
This agreement was voided after Seven of Nine stole a shuttlecraft and entered B'omar space in response to a Borg signal. In response to these events, within the hour the B'omar doubled the number of ships patrolling their borders and increased the sensitivity perimeter grid.
Ultimately, Voyager was forced to take the three-month journey around B'omar space. It was required to stay five light years from the border at all times lest its maneuvering were considered an act of aggression. (VOY: "The Raven")