From Warhammer 40k - Lexicanum
The Tarren Suppression was a battle of the Horus Heresy, taking place in 011.M31.
Taking place on the traitor-sworn world of Tarren IV, the battle saw a loyalist retribution fleet move in to crush the treachery. The loyalists managed to quickly occupy the world's capital of Brandstat, brutally stamping out anti-Imperial sentiment. Key to the suppression are the Titans of the Legio Defensor which make examples of traitor cities by blasting them to flaming ruin.
Later on however, a traitor force of Emperor's Children, Legio Cybernetica, and Legio Mortis arrive to "liberate" the world in an event known as the Relief of Brandstat.
- 1: Adeptus Titanicus (2018) Rulebook pg. 17