What does the idiom "a county is a county" mean? What are the allusions?

This poem comes from Li Shangyin's poem "Pity a dead body, which has been reported to Zhou Shi for Jinyang", which means that Feng Xiaolian was a high-latitude imperial concubine after the Northern Qi Dynasty in the Southern and Northern Dynasties. She used to be a maid around the Queen Mu, but later she jumped on a branch and became a phoenix, gathering 3,000 pets. Her charm and absurdity led to the demise of the Northern Qi Empire. The Northern Wei Dynasty was roughly along the border between Shanxi and Shaanxi provinces, with a section of the Yellow River as the boundary, and the north and south were divided into two countries. The Eastern Wei occupied the land east of the Yellow River and north of Huaishui, and the Western Wei occupied the Guanlong area west of the Yellow River and north of the Qinling Mountains. The Eastern Wei Dynasty established the capital, which is today's Linzhang County, Henan Province. Chang 'an, the capital of the Western Wei Dynasty, was a prosperous place for emperors of all dynasties. The strength of the Western Wei Dynasty was far less than that of the Eastern Wei Dynasty, and even the Liang regime in the Southern Dynasty was stronger than the Western Wei Dynasty. The Northern Qi Dynasty was established by Gao Yang's seizure of the Eastern Wei regime, and it was the most powerful. The Northern Zhou Dynasty was founded by Yu Wenjue to defend the regime of the Western Wei Dynasty, with the smallest strength. When Yu Wenjue established the Northern Zhou Dynasty, Nanliang was also replaced by Chen. However, before long, the strength of Beiqi and Beizhou gradually leveled off. On the one hand, Beiqi was appropriated by the Southern Dynasties, on the other hand, Beitong crossed the Qinling Mountains and plundered Hanzhong and Sichuan. At that time, Gao Wei became the emperor of the Northern Qi Dynasty, and Feng Xiaolian soon became his concubine. In the seventeenth year of the founding of Beiqi, Gao Wei ascended the throne and was the queen of Beiqi. He is a standard dude, a drunken beauty, dissolute and romantic, living a luxurious and romantic life, strung pearls into glittering gowns, and inlaid with precious stones on jade chariots, hanging out with the queen's palace princess day and night, and living a life of drunkenness. Feng Xiaolian is a maid around Queen Mu. At that time, Gao Wei was in love with Cao, who was good at playing pipa. In order to resist Cao Zhaoyi, Queen Mu gave Feng Xiaolian to Gao Wei. As a result, a famous idiom of China was verified: Drink poison to quench thirst. Feng Xiaolian received strict music and dance training since childhood and was influenced by a set of methods to confuse men. After he entered the palace, he became more accustomed to the tricks of concubines vying for favor and beauty, so he developed a new method to flatter, which exposed the late ruler of Beiqi to a fresh curiosity and was fascinated. Feng Xiaolian is proficient in the structure and vein system of human body. When she waited on Queen Mu, she tried to eliminate physical fatigue for the hostess by means of mallet, rolling, pulling and carrying. Over time, she developed a set of self-taught massage methods. Later, when she swam around her high-latitude body with her soft little hands, the romantic emperor, who was actively looking for excitement all day, suddenly had a passive sense of fun and happiness. Besides these artificial conditions, it is said that Feng Xiaolian has natural capital. Her body is curvy and uneven. In the cold season of winter, it is as soft as cotton and as warm as fire. When it is hot in summer, it is as hard as jade and as cold as ice. Hugs, pillows, caresses, or kisses are all witty attempts. She is a natural beauty, which is the main capital for her to get a unique pet soon. In addition to building luxurious palaces, indulging in singing and dancing and reveling, it is not uncommon in all dynasties, without rest or extravagance. Even Gao Wei, the queen of Qi State, often put Feng Xiaolian in her arms or on her lap when discussing with ministers, making the ministers who discussed often blush and incoherent, and come back in vain. After the Northern Zhou Emperor ascended the throne, he saw that the ruler of the Northern Qi Dynasty was fatuous at high latitude, and personally led an army to attack Pingyang (now Linfen) and Jinyang (now Taiyuan). After the Northern Zhou Dynasty occupied Pingyang, Gao Wei of the Northern Qi Dynasty actually said such a sentence: "As long as Feng Xiaolian is safe, what's the harm of defeat!" "The solo music is not as good as the public music", and Gao Wei, the queen of the Northern Qi Dynasty, is really naive. He thinks that a lovely person like Feng Xiaolian is the only one who appreciates her beautiful amorous feelings, which is a rare treasure. If all men in the world can appreciate her natural beauty, it will be great beauty. So, after some design and arrangement, Feng Xiaolian stood on the Longjitang, and all the rich people came to see the beautiful scenery, at a price of 1,000 yuan. This is another great achievement, which made the Northern Zhou Emperor laugh. Laugh! Make him laugh! Gao Wei still went hunting in Tianchi with Feng Xiaolian in his own way. The courtiers told him: "Winter has arrived, and the Northern Zhou army has returned to Chang 'an, which is the time to recover Pingyang." Gao Wei is hesitant about this. Feng Xiaolian thought that war was as fun as hunting, so he urged Gauguin to personally lead troops to counterattack Pingyang. Gauguin obeyed naturally, so Feng Xiaolian accompanied him in uniform. Beiqi soldiers surrounded Pingyang City. In order to recover lost territory and resist foreign aggression, the soldiers of the Northern Qi Dynasty bravely dug tunnels and erected ladders. Liang Shiyan, a general of the Northern Zhou Dynasty who stayed in Pingyang, led a limited number of soldiers to defend the city to the death, but he was in danger under the desperate charge of the soldiers of the Northern Qi Dynasty. Seeing that Gao Wei was about to issue a general attack order, Pingyang was about to return to the embrace of the Northern Qi Dynasty. Feng Xiaolian thought that it was getting late and could no longer watch the grand occasion of siege, and asked to siege again the next day. The next day, it was dark, the north wind roared, the first snow fell, and the earth gradually became silvery white. Feng Xiaolian also thinks that the climate is not good and demands that the siege be suspended. Little did they know that dark nights or bad weather were the best time to attack in military operations. Because of women's opinions, the army of Beiqi lost two good opportunities for no reason. By the time the snow and fog cleared, Emperor Wu of the Northern Zhou Dynasty had led an army to Pingyang. The two armies fought bloody battles for several days, and the Qi army was defeated and retreated into Jinyang. The vigorous battle of Pingyang ended in the fiasco of the Qi army. After the Pingyang War, Emperor Wudi of the Northern Zhou Dynasty fought fiercely in the cold, and prepared to take his troops back to Chang 'an to rest. Liang Shiyan admonished the horse, thinking that it is now or never, and he should take Jinyang, the important town of Beiqi. Emperor Wu of the Northern Zhou Dynasty adopted Liang Shiyan's opinion and pursued the Qi army with his unified army, forcing Jinyang to the gate. What Emperor Wu of Zhou did was in sharp contrast with Gao Wei, the ruler of the Northern Qi Dynasty. He knew that he should seize the opportunity, and his first preparation for rest was out of love for soldiers, unlike Gao Wei, who only wanted to satisfy Feng Xiaolian's women's opinions. In the early days of Jinyang Campaign, Jinyang was an important town in the north which was operated by Northern Qi for many years. The city is tall, deep and heavily guarded, and there are a lot of grain and grain equipment in the city. There is no problem supporting it for a year or so. Zhou Bing is far away, and it is winter. It won't be long before he resigns. Gao Wei and other northern Zhou armies retreated automatically. Unexpectedly, the northern Zhou army showed no signs of retreating, nor did it mean to take the initiative to attack. So Gao Wei, the ruler of Qi, ordered the construction of a towering overpass in the city, and often boarded the bridge with Feng Xiaolian to look out at the enemy outside the city. After getting off the bridge, he hid in the gentle village arranged by Feng Xiaolian for him. At this time, Feng Xiaolian selected a group of handmaids with good looks and excellent figure for him, trained them, and soon formed a strip troupe to let Gauguin watch their dances to relieve their worries. Gao Wei, the master of the Qi Dynasty, even said brazenly, "I can be clear-headed and full of energy." One day, the wooden overpass suddenly collapsed, which is normal under the wind and rain. But Feng Xiaolian thought it was ominous, and he was frightened. He repeatedly asked the deceased to give up Jinyang and return to Yecheng. Unexpectedly, Cushman & Wakefield once again ignored the national interests and followed Feng Xiaolian's advice and returned to Yecheng. The Northern Zhou Dynasty easily captured Jinyang, an important town in the Northern Qi Dynasty. The Northern Zhou Dynasty went straight to Yecheng. Gaowei retreated to Yecheng with100000 elite soldiers. Don't love mountains and rivers, the emperor who loves beauty is "anxious". While praying for the blessing of Bodhisattva, he passed the throne to Prince Gaofeng, and fled to Qingzhou from his own city with Feng Xiaolian, and successfully won Yecheng in the Northern Zhou Dynasty. Later, after the demise of the Northern Qi Dynasty, Gao Wei, Prince Gaofeng, Feng Xiaolian and others were captured, the Northern Qi Dynasty perished, and the Yellow River Basin was reunified. Li Shangyin, a poet in the Tang Dynasty, wrote two poems "Northern Qi": If you laugh, you will die. Why bother with thorns? When the northern Zhou army entered the palace that night, the battle report of the northern Zhou army advancing to Jinyang has been issued. Secondly, I know that I am no worse than the enemy, and the whole city wears glorious clothes at most; Yang had fallen far behind the left, and Maple flew to ask the left to go hunting again. Gao Wei was sent to Chang 'an and was finally killed after being humiliated. Feng Xiaolian was paid by Yu Wenda, the younger brother of the Northern Zhou Emperor, and soon Yu Wenda was killed by Yang Jian. She also became the wing of Li Xun, a military commander, and was tortured by her first wife. Besides cooking, chopping wood, cooking and washing clothes, she was scolded and beaten from time to time. How could Feng Xiaolian withstand such devastation and finally hang herself? It was a blue day, and that night was a full moon.