Algeron III was a Romulan planet. In the late 23rd century, Algeron III was destroyed by an isolytic subspace weapon. A Graymel scourge vessel was losing a battle to a Romulan bird-of-prey 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. (ST - The Lost Era novel: Serpents Among the Ruins, ST - Typhon Pact novel: Raise the Dawn)