Born in UC 0046, Crowley Hamon formed a deep personal and professional partnership with Ramba Ral. Her early years included performing as a nightclub singer in Texas Colony during UC 0071, where her emotionally resonant vocals coincided with Ral's assignment, forging their initial bond. She transitioned into Ral's military operations as his strategic adviser and coordinator aboard the Gallop-class land battleship throughout the One Year War, managing communications, logistics, and battlefield coordination during Earth descent missions.

In the North American campaign, Hamon encountered a deserting Amuro Ray near Sodom, offering him food and expressing compassion for his plight. After Ramba Ral's combat death, she assumed command of his forces, pivoting to aggressive tactics. She orchestrated a suicide assault using the Gallop's cargo unit as a battering ram against the White Base. In the final clash, she piloted a Magella Top—the detached turret of a Magella Attack Tank—aiming to destroy the Gundam as it tried to stop the collision. Ryu Jose interrupted this maneuver by crashing a Core Fighter into her position, killing them both.

Despite typically holding no formal rank—though some adaptations list her as First Lieutenant—Hamon wielded significant influence within Ral's unit and demonstrated expertise in operating vehicles like the Magella Attack Tank. Her relationship with Ramba Ral, marked by mutual respect and profound commitment, saw him affectionately call her "Lady Hamon." This dynamic made her a stabilizing force in his command until his demise radically shifted her emotional state and tactics.

The Origin expanded narrative detailed her pre-war activities in Texas Colony and her operational partnership with Ramba Ral during Zeon's mobile suit development phase, reinforcing her dual identity as a cultural figure in the colonies and a strategic military asset before the war.