After officially becoming Duke Aegir, Ferdinand asked Emperor Edelgard if she would make him her minister of foreign affairs rather than her prime minister. She granted his wish, and his first task in his new position was to negotiate with Petra, who had inherited the throne of Brigid and declared her Kingdom's freedom from Imperial vassalage. Ferdinand and Petra collaborated to deepen the friendship between their nations and forge a strong, enduring alliance. As a symbol of the nations' friendship, Ferdinand and Petra took up residence together in Nuvelle, on the western fringe of Fodlan. It is said that they negotiated for years to achieve this compromise.