Following Unicron's assault on Cybertron, the Decepticons, who had suffered far worse than the Autobots, found themselves at a terrible disadvantage. Suddenly missing their leader Galvatron and badly decimated, they retreated from Cybertron rather than stay and get wiped out. Eventually, they ended up regrouping on the planet Charr, whose location they attempted to keep secret. There, they wallowed in misery and slowly rusted away as their energon supply dwindled.
When the Quintessons kidnapped several Transformers (along with Spike) at the Intergalactic Olympics, the Autobots immediately suspected the Decepticons. Eventually, they managed to capture some Decepticons, and obtained Charr's location (Rodimus overlooked it initially, thinking it was a smudge on the glass). Rodimus and Grimlock went to spy on the Decepticons, but instead of finding their missing friends, they saw only that the Decepticons had nowhere near enough energy to attack anyone. Eventually, Galvatron was recovered and brought back to Charr by Cyclonus and the Sweeps. Charr became the base of the Decepticons for some time after that.