Vitrol Minor
Vitrol Minor was wiped out by the Seedle Warriors, sent by the High Council of Time Lords.
Having tracked Azmael to Vitrol Minor, the Seedle Warriors set about eliminating the populace while Azmael was smuggled off-world, justifying the genocide as the elimination of witnesses to the destruction of a Time Lord. They spent three days murdering before they finally noticed on the fourth day that Azmael had escaped.
When Azmael confronted the High Council about interfering with other planets, the Council was able to bribe their way out of it, creating evidence that Azmael had hired the Seedle warriors to eliminate the population for Vitrol Minor's mineral wealth, even though it had none. (PROSE: The Twin Dilemma)