Zheng Mingxi began his historical trajectory not as a revolutionary ideologue, but as a disgraced former officer of the Ming Imperial Army. Cashiered for his unorthodox tactics and "flexible" thinking which clashed with the rigid traditions of the Chinese military, he lived in relative obscurity as a logging magnate in the northern province of Bei Senlin. However, as the Heshian rebellion against the "Chastity Directive" morphed into open war in 1783, the desperate rebel leadership turned to him. Recognizing that their disorganized militias stood no chance against the professional Imperial forces under General Zhao Tianwu, the Second Regional Assembly appointed Mingxi as the commander of the "Provincial Army," pinning their hopes on the very tactical flexibility that had ruined his previous career.

Mingxi’s military genius was forged in the fires of near-defeat. His initial campaign to besiege the capital of Huangcheng ended in a disastrous rout, forcing him to retreat into the freezing Zhai Gu mountains with a disintegrating army. It was there, in the winter of 1783, that he executed the masterstroke that defined the war. Luring the overconfident Imperial forces into a narrow valley, he launched a devastating ambush that annihilated a column of 8,000 Ming soldiers. This victory at the Battle of Zhai Gu Valley saved the revolution from extinction and shifted the momentum permanently in the rebels' favor. Mingxi subsequently secured the north by crushing the Ming's native allies at Lake Tianchi and, with British naval support, forced the final surrender of Imperial forces at Sēnlín Wān in 1785, effectively ending Chinese rule in the New World.

Following the war, Mingxi initially sought to return to private life, but the internal divisions of the new republic demanded a unifying figure. In 1794, amidst squabbles between the merchant "Unionist" faction and the aristocratic "National Republicans," the Diet elected him as the first head of state. To satisfy both the conservative desire for a sovereign and the liberal demand for democracy, he accepted the unique title of "Elected Emperor." His reign, known as the "Years of Harmony," was characterized by a delicate political balancing act; he appointed a cabinet mixed with merchants and landowners, stabilized the economy through the creation of a National Bank, and oversaw the construction of a new, centrally located capital, Pingcheng. By the time he moved his court to the new city in 1814, Mingxi had transformed a chaotic rebellion into a stable, rising power in the Pacific.