Maximus was born to two geneticists Agon and Rynda. Exposed to Terrigen Mist when he was an infant he didn't show any change in his powers. However, when he grew, his powers developed, but he also developed an anti-social behavior.
When he was 16, his brother Black Bolt was released from his protective chamber in which he had been kept in due to his destructive voice. When Black Bolt was released, Maximus attempted to make Black Bolt use his voice, but was unsuccessful. Some time later, Black Bolt witnessed Maximus making a pact with the Kree, who were responsible for altering the Inhuman's DNA. He tried to stop the Kree who was escaping. Black Bolt used his sonic scream and the ship crashed, and killed several members of the Genetics Council. The voice also affected Maximus' sanity and suppressing his powers. When Black Bolt took to the throne, Maximus vowed to throw him off the crown.
Maximus' first plan was experimenting on the Alpha Primitives. Maximus then created the Trikon, three destructive energy beings. While the Inhumans were distracted with Attilan, Maximus was able to drive the Royal Family out of the city in search for Medusa while she was on a mission to study human society. Maximus ruled Attilan for the while the Royal Family was gone. Maximus was confident in his ruling, so he called the Royal Family back, but Black Bolt immediately stole back the crown. Maximus was angered, and activated his Atmo-Gun, a machine that would kill all living things other than the Inhumans. However, the machine had no effect and in anger, used the machine to create a "negative zone" which imprisoned the Inhumans. Black Bolt used his voice to destroy the barrier.