History

The First Robot War
A great war once occurred in which colossal robots called Gigantors terrorized the land. To defeat the immanent evil, an extremely powerful robot, called The General, was created.

The General
An extremely powerful robot created to save the world from the Gigantors. The General swiftly fulfilled his task, ending the First Robot War, but his power grew too great, and he could not be controlled. Thus, before the damage First Robot War could heal, the second began.

The Eon Family
While The General was reeking havoc in a far off land, Eon, the first to don The Iron Fist, was training to master its power. Surrendering to the Fist's power, he was able to destroy The General, but it cost him his own life.

The General's forces from there on hunted the Eon family members, felling them one by one. Then, about a decade before the start of the show's events take place, the last member of the Eon Family, Marty's real father, fell in battle, defending Marty's escape.

Charlie ran with Marty away from the violent final scene of the baby's father's demise, and became his surrogate father. Charlie raised Marty the best he could, but as The General's forces never would stop searching for him, he had to take up the humble job of scavenging The Great Desert to avoid their notice.

Future Preparation
Gaff, the 9th Guardian of the Eon Family, was entrusted to find Eon's successor when the time came.

The General's forces know that an Eon family member defeated the general, and so will stop at nothing to eliminate any successor to the family line.

Reference

 * Episode 11 (Confronting Fate)