In the age following the departure of the Knights of Cybertron, Solus Prime was one of the many Primes that arose on prehistoric Cybertron, tribal leaders who gathered like-minded followers. Heavy Approximately twelve million years ago, Solus and her tribe joined a coalition of like-minded Primes—Nexus, Vector, Alchemist Prime, and Alpha Trion—and founded the village that would eventually become the Crystal City.