Gasko
- Located in Beta Quadrant near Federation, Klingon, and Romulan space (ENT Novel: To Brave the Storm; DIS: "Magic to Make the Sanest Man Go Mad", "The War Without, The War Within"; TLE Novel: Serpents Among the Ruins)
- Located within Romulan space by 2159 (ENT Novel: To Brave the Storm)
- Ceded to Federation space with end of Earth-Romulan War
- Occupied by Klingon Empire during Federation-Klingon War (DIS: "Magic to Make the Sanest Man Go Mad", "The War Without, The War Within")
- Recaptured by Federation following end of war
- Returned to Romulan Star Empire by 2311 (TLE Novel: Serpents Among the Ruins)