In 206 BC, following the collapse of the once-mighty Qin Empire, Chinese history entered a new phase. At that time, Xiang Yu, the Hegemon-King of Western Chu, and Liu Bang, the King of Han, formed two rival factions, sparking the famous Chu-Han Contention for control of the empire. Throughout this nearly five-year-long war, the Han general Han Xin demonstrated exceptional strategic brilliance and military acumen, fulfilling the ideal of "commanding a million troops from the command tent, winning every battle and capturing every objective."

In September of the 8th year of Tianhui (the 4th year of Jianyan in the Southern Song Dynasty, 1130), the Jin army defeated a Song counteroffensive in the Fuping region (north of present-day Fuping County, Shaanxi), as part of their campaign to conquer Shaanxi.

Shangdang, known as the "spine of the world," commands a strategic view over central China and forms the vital link to Hedong and Bingzhou, earning it the title "the throat of the state of Jin." Its terrain is exceptionally formidable, making it a coveted battleground for military strategists since ancient times. In 402 BC, the states of Wei, Zhao, and Han divided the state of Jin among themselves, and Shangdang fell under Han's control. However, the rising power of Qin had long coveted Shangdang. In 280 BC, the Qin general Bai Qi penetrated deep into Shangdang and captured Guanglang City (modern-day Kangying Village in Gaoping).

When the Hongwu Emperor (Ming Taizu) was in power, he learned from historical lessons about eunuchs monopolizing power and causing state chaos. He established a rule forbidding eunuchs from interfering in state affairs. He inscribed this rule on a large iron plaque and hung it in the palace, hoping his descendants would abide by it generation after generation. However, during the reign of the Yongle Emperor (Ming Chengzu), this rule was abolished.

Among the seven major warring states, the state of Qin lagged behind the various feudal states in the Central Plains in politics, economy, and culture. Its neighboring state of Wei was stronger than Qin and had seized a large area of land west of the Yellow River from Qin.In 361 BC, Duke Xiao of Qin, the new ruler of Qin, ascended the throne. Determined to strengthen his state, he first sought out talented individuals. He issued an edict stating: "Whether a native of Qin or a foreign guest, whoever can devise a way to make Qin rich and powerful shall be appointed to an official position."

During the Southern and Northern Dynasties, not only was the twelve-animal zodiac used for marking years, but the renowned scholar Shen Jiong also composed China's first delightful poem featuring all twelve zodiac animals: "Mouse tracks leave dust on the desk, ox and sheep return at dusk. Tiger roars sit in the empty valley, rabbit moon shines through the window. Dragon marshes stretch far with verdant green, snake winds near the willow trees. Horse orchids are just picked from afar, sheep carry spring seedlings. Monkeys offer chestnuts and fragrant fruits, rooster's crow draws a clear cup. Dog embodies a carefree spirit, pig peers from the window in leisure."

In 262 BC, King Zhaoxiang of Qin dispatched the general Bai Qi to attack the state of Han, capturing the city of Yewang (present-day Qinyang, Henan). This cut off the connection between Shangdang Commandery (its seat located in present-day Changzhi, Shanxi) and the Han capital, placing Shangdang in a critical situation. The Han military leaders in Shangdang refused to surrender to Qin and sent an envoy to present the maps of Shangdang to the state of Zhao.

With Lin Xiangru and Lian Po working together to defend the state of Zhao, Qin indeed dared not to invade. However, Qin still managed to seize considerable territory from the states of Chu and Wei. At that time, real power in Qin lay in the hands of the Queen Dowager and her brother, Lord Rang (Wei Ran, "Rang" pronounced "ráng"). In 270 BC, Lord Rang planned to send troops to attack the state of Qi.

King Zhaoxiang of Qin was determined to subjugate the state of Zhao, repeatedly invading its borders and seizing several territories. In 279 BC, he devised another scheme, inviting King Huiwen of Zhao to meet him at Mianchi (west of present-day Mianchi County, Henan Province; "Mian" pronounced "miǎn") in Qin territory. Initially, King Huiwen of Zhao feared being detained by Qin and hesitated to go. However, both the general Lian Po and the minister Lin Xiangru believed that refusing the invitation would only show weakness to Qin.

Although the state of Qi had suffered a defeat at Changshao, it did not affect Duke Huan of Qi's later status as a hegemon. Over ten years later, the northern state of Yan (its capital in present-day Beijing) sent an envoy to request military aid, reporting that their state had been invaded and defeated by the Shanrong tribe nearby. Duke Huan decided to lead a large army to rescue Yan. In 663 BC, when Qi's army arrived in Yan, the Shanrong had already looted people and treasures and retreated.