This source, though popularly accepted as historical canon, makes some pretty outstanding claims about Maul. It claims that he escaped Naboo somehow and went into hiding on a garbage planet. There he constructed himself robotic legs and slowly descended into madness before being rescued by his brother ten years later. The two then supposedly amassed a mercenary army and staged a coup d'etat on Mandalore (but their regime fell shortly afterwards). Are there any independent sources that verify this narrative?
Maul reawakened and, with all of his anger, was able to use the Force to acquire a six-legged arachnid-like cybernetic apparatus to replace his lost lower body.[37] For twelve years, Maul's memories were lost and he was in a state of near-madness, eating only the small animals that came to the cave, aided in obtaining shelter and sustenance only by Morley, but the only thing he remembered was Obi-Wan Kenobi and how he took his legs.[8][37]
This source seems to confirm.
Doesn't matter, because the movies will only work with information given in other movies from this point forward.