Critter's Universe
Eleven light-years from Port Natal (a Golgan planet) there is a small dust cloud which emits a healthy amount of radio waves. In the vastness of interstellar space these clouds are not uncommon, so little attention beyond marking it as a astronomical oddity. Until Jorj Critter flew into it while prospecting for anything interesting. This region of space, it turned out, was an area in which space had formed a side bubble (a pocket universe), and where physical laws were somewhat different. Critter's Universe, which is only about a hundred light-years across did coexist with a large section of the Golgan Republik, who, having learned about this, decided they should own it. 

In response, Jorj Critter claimed the area and, with a few of his close prospecting friends, defended the the entrance gateway using the peculiar physical properties of the alternate universe. The Republik Fleet never got within a billion kilometers of the Gateway before being reduced to solar ash. Hastily withdrawing their forces from the Gateway, the Golgans began cultivating good feelings with Jorj Critter and left the matter at that. Pocket universes are  artificially-created universes that exist within the bounds of another universe.