Warfare broke out all over the northern border of the Dajing Dynasty. Barbarian cavalry knocked the pass year after year, and the people on the border were displaced. The old Zhenbei Marquis Shen Yi died in battle in Mobei. There was no male in the Marquis's house to inherit the title. The civil servant group in the court controlled the power and regarded the general as a thorn in his side. They actually wanted to abolish the Zhenbei Marquis's mansion and abandon Yanmen Pass. His legitimate daughter, Shen Jinghong, practiced martial arts with her father since she was a child. She was familiar with military books and was as good at strategy and martial arts as any man. She broke through the shackles of the ancestral system that "women are not allowed to hold nobility or serve in the army." At that time, the Yanbei Army's equipment was backward and there was a shortage of food and grass. The court was deducting military pay and restricting everything. The barbarians were watching with eager eyes, and the nomadic tribes in the north had their own agendas. Shen Jinghong used his iron-blooded skills to organize the army, improve weapons, and recruit refugees into the army; he used gentle wisdom to connect with the nomadic tribes in the north and form an anti-barbarian alliance; he used thunderous power to repel the barbarian cavalry several times and defended Yanmen. While she was fighting bloody battles on the battlefield, she was also playing games with the treacherous prime minister above the court, exposing his "collaboration with the enemy" conspiracy, and conveying the true battle situation in the north to the young emperor. In the end, Shen Jinghong led the Yanbei Army and the tribal alliance to launch the Northern Expedition, completely defeating the main force of the barbarians and regaining thousands of miles of lost territory in the north. The young emperor took advantage of this opportunity to wipe out the civil servant clique in the court and restore the prestige of the military generals. Shen Jinghong was canonized as the eldest princess of Zhenbei for her outstanding military exploits, and she stayed in the northern border forever. The criticism of "women in command" in the past finally became the "Guardian of Yanmen" among the people in the northern border. The northern border of Dajing ushered in a hundred years of peace, and women joining the army became a unique iron-blooded scenery in the northern border.
