Jill hails from the Talrega region of Daein, and is the daughter of the famed Wyvern Lord, general Shiharam. Jill aspires to be a renowned Wyvern Lord like her father, and first appears as a novice-ranked Wyvern Rider.
During the Mad King’s war, after the Greil Mercenaries were rescued by Goldoan soldiers and Prince Kurthnaga, Jill defected from the Daein army when she spots Ike's forces battling pirate Ravens and joined the liberation effort for Crimea. She later reveals that her main purpose for joining the battle was to experience the thrill of hunting laguz down, alongside an underlying desire to clinch glory for herself. Despite this, however, she chooses to continue fighting alongside the Crimean army after being exposed to the fact that the laguz race is not comprised of the mindless monsters she initially perceives them to be.