Northern Zhou and Northern Qi were old enemies of China during the Southern and Northern Dynasties, and together with their predecessors Western Wei and Eastern Wei, the two countries fought each other for decades without winning or losing, but overall, the Northern Qi state was slightly stronger than northern Zhou, but the final result was that Northern Zhou destroyed Northern Qi, which is a well-known thing.
The third emperor of Northern Zhou, and the emperor of northern Zhou Wu, Yu Wenyong, made great efforts to govern during the reign of Emperor Yuwen Yong of Northern Zhou, so that the strength of the Northern Zhou state continued to rise, and the fifth emperor of Northern Qi at the same time, and the northern Qi emperor Gao Wei was incompetent, so the northern Qi state power continued to decline, so the Northern Zhou Wu Emperor took advantage of this once-in-a-lifetime opportunity in 576 AD to launch a war of annihilation against Northern Qi, successfully destroyed Northern Qi in the following year, and unified northern China.
Northern Zhou Wu Emperor Yuwen Yong destroyed Northern Qi and unified the north, although he was a very powerful and great emperor, but you must know that an emperor can achieve great achievements, all because of the heroes who assisted this emperor, those great emperors in Chinese history are all like this, so when it comes to Northern Zhou Wu emperor destroying Northern Qi and unifying the north, it is necessary to say that the first hero of Northern Zhou to destroy Northern Qi, his name is Yuwen Xian.

From Yuwen Xian's surname, it can be guessed that he is actually a member of the Northern Zhou royal family, who is the half-brother of Emperor Wu of Northern Zhou, the fifth son of Yuwen Tai, the founder of the Northern Zhou Dynasty, who is only one year younger than Emperor Wu of Northern Zhou. Yuwen Xian showed amazing talent from an early age, and Wen Tao Wuluo was the most outstanding among Yu Wentai's many sons, and repeatedly publicly praised Yu Wenxian as the most like himself.
Yuwen Tai was a powerful vassal of the Western Wei Dynasty before his death, controlling the real power of Western Wei, and the entire Western Wei Dynasty experienced three generations of emperors, all of whom were puppets of Yuwen Tai, and in order to consolidate his control over Western Wei, Yuwen Tai installed cronies throughout the imperial court and wantonly sealed his sons, and Yuwen Xian was the Duke of Ancheng County.
Later, Yuwen Tai died before he could claim the title of emperor, or he did not intend to be called emperor at all, or that he did not have the heart to be called emperor from beginning to end, but just wanted to be a powerful courtier, and everything he had before he was born was inherited by his nephew Yuwen Hu. After Yuwen Hu became a vassal of Western Wei, he deposed the last emperor of Western Wei, Yuan Kuo, but he emulated Yuwen Tai and did not call himself emperor, but instead installed Yuwen Tai's third son and cousin Yuwen Jue as emperor, known as Emperor Xiaomin of Northern Zhou, and thus Northern Zhou replaced Western Wei.
After the establishment of Northern Zhou, Yuwen Xian, because of his status as a member of the imperial family, was given important positions such as Grand General of the Hussars and Kaifu Yi Tongsan Division, and he was ordered by Yuwen Hu to lead an army to resist northern Qi's attack on Northern Zhou, which was Yuwen Xian's first time on the battlefield.
Yu Wenxian showed amazing military talent on the battlefield, as if he was a natural military expert, he commanded the Northern Zhou army many times, severely damaged the Northern Qi army, and many of them won more with less, so Yu Wenxian's prestige in the Northern Zhou court became higher and higher. In addition, Yuwen Xian shared the hardships with the soldiers on the battlefield and cared about every soldier, so he was deeply respected and loved by the Northern Zhou army.
Yuwen Hu was one of the most powerful courtiers in Chinese history, he was a powerful minister of the Three Dynasties, the three emperors of northern Zhou, Yuwen Jue, the emperor of Northern Zhou, Yuwen Yu, the emperor of Northern Zhou, and Yuwen Yu, the emperor of Northern Zhou, were all his puppets, and he was always calling for wind and rain in Northern Zhou, but because Northern Zhou was often threatened by Northern Qi, and his cousin Yuwen Xian had excellent military skills, so the chancellor Yuwen Hu had to rely on his assistance to stabilize his control over Northern Zhou.
In 572, Emperor Wu of Northern Zhou, who had been a puppet for 12 years, finally found an opportunity to kill his cousin and powerful minister Yuwen Hu, ending his puppet status, and from then on Emperor Wu of Northern Zhou could finally show his ambitions and realize his dreams, at this time he needed the future assistance of a virtuous and practical scholar, and his half-brother Yuwen Xian was one of them, and he had great respect and dependence on this half-brother.
At that time, China was in the situation of the three-legged Northern Zhou, Northern Qi, and Southern Chen Dynasties, northern Qi, under the rule of Gao Wei, the lord of the Late Emperor, and southern Chen was under the rule of the Ming Emperor Chen Xuan emperor Chen Huan, so Emperor Wu of Northern Zhou believed that this was a once-in-a-lifetime opportunity to destroy Northern Qi. Subsequently, Emperor Wu of Northern Zhou focused on reforming the army, so that the military strength of Northern Zhou made a qualitative leap in just a few years.
In 576, Emperor Wu of Northern Zhou, Yuwen Xian and other sages and generals made a plan to destroy Qi, and put it into action, with Yu Wenxian as the commander of the army, and then launched a fierce attack on Northern Qi. At that time, the Northern Qi Empress had already killed Gao Changgong and Hu Luguang, the only two generals who could compete with Yuwen Xian, without these two people, the Northern Zhou army commanded by Yu Wenxian was so strong that it successfully destroyed Northern Qi the following year.
In Chinese history, it is quite rare for one divided dynasty to be able to wipe out another in less than two years, which shows that Yuwen Xian was really a powerful military expert.
After Northern Zhou destroyed Northern Qi, Emperor Wu of Northern Zhou rewarded meritorious men for their meritorious deeds, and Yuwen Xian was not surprised to be ranked first meritorious and crowned the King of Qi, with the fiefdom of Yicheng (邺城, in modern Handan, Hebei Province) and its surrounding areas.
Yu Wenxian was not only militarily talented, but also had sophisticated political thinking, and he was well aware of his high merits and intended to retire from The Northern Zhou Emperor, but before he could speak, the Northern Zhou Emperor died of illness, and the heir to the throne was the eldest son, Northern Zhou Xuan Emperor Yuwen Yun.
Yuwen Xian thought about it and proposed to Emperor Xuan of Northern Zhou to retire, but Emperor Xuan of Northern Zhou verbally agreed, and in his heart he was already silently contemplating how to kill Yu Wenxian.
In August 578, Emperor Xuan of Northern Zhou murdered Yuwen Xian for treason, and Yu Wenxian was only 34 years old when he died, and his sons were also implicated and executed.
In the past dynasties of China, the situation of meritorious people being killed has occurred from time to time, and Yuwen Xian, as the first hero of northern Zhou to destroy Northern Qi, was killed for his high merits, which is a microcosm of those heroes who were killed in history.