Algeron III was a Romulan planet destroyed by an isolytic subspace weapon, or metaweapon some time prior to the Tomed Incident in 2311. An unknown starship was losing a battle to a Romulan one in the system and proceeded to detonate an experimental metaweapon in order to try to turn the tides. The destructive power of this weapon was not known by the Klingon people. A rip in subspace formed near Algeron III and sliced through and destroyed the planet.

Romulan Space Station Algeron was later constructed in the Algeron System that served as a site for peace talks between the United Federation of Planets, Romulan Star Empire, and Klingon Empire in 2311. The station could also presumably be used to study the Algeron Effect, a result of the isolytic subspace weapon's detonation.

(TLE novel: Serpents Among the Ruins)