In 307 BC, Ying Ji's older half-brother, King Wu, unexpectedly died after breaking his shin bones while trying to show off his physical prowess by lifting a heavy bronze cauldron in the Zhou palace at Wangcheng.

King Wu died young and childless, hence placing the state of Qin into a succession crisis, with a number of princes now eligible to claim the throne.

Furthermore, Prince Ji's maternal uncle, Wei Ran (魏冉), was a general in command of a significant Qin military forces, and helped suppressing most of his nephew's political opponents.

In his first year as ruler (306 BC), King Zhaoxiang accepted the counsel of the Right Chancellor, Gan Mao (甘茂), who advocated the return of the Wusui (武遂) region back to the state of Han.

The plan was opposed by two other officials Xiang Shou (向壽) and Gongsun Shi (公孫奭), who both despised Gan Mao greatly and proceeded to badmouth him repeatedly.

In 300 BC, King Zhaoxiang sent his uncle Mi Rong to capture Xiangcheng (襄城), killing 30,000 enemy and the Chu general Jing Que (景缺) in the process.

Due to this defeat, in 299 BC King Huai of Chu was forced to go to Wu Pass (武關) to negotiate terms with Qin, but along the way was abducted and taken to Xianyang instead.

In 279 BC, Qin generals Bai Qi (白起) and Zhang Ruo (張若) launched amphibious assaults on Chu from two different fronts, capturing the cities of Deng (鄧), Yan (鄢, Chu's secondary capital at the time) and Xiling (西陵), during which Bai Qi flooded the city of Yan with a redirected river, drowning hundreds of thousands of people.

Qin then permanently annexed the vast lands around Dongting Lake, south of the Yangtze River and north up towards Anlu (安陸), where the new Nan Commandery (南郡) was established.

In 301 BC, Qin again attacked Han, led by King Zhaoxiang's uncle, Wei Ran, and occupied the city of Rang (穰城).

In 290 BC, King Zhaoxiang sent Sima Cuo (司馬錯), who captured Zhi (軹) from Wei and Deng (鄧) from Han, before joining with Bai Qi to seize Yuanqu again.

In 264 BC, King Zhaoxiang sent Bai Qi to attack Han, capturing nine cities including Xingcheng (陘城) and killing 50,000 of the enemy, enabling Qin to blockade the routes around southern Taihang Mountains.

King Huanhui of Han was fearful of the Qin military prowess and decided to concede Shangdang, but the local commanders refused to do so and instead surrendered the region to the state of Zhao.

The struggle for control of Shangdang triggered direct conflicts between Qin and Zhao, then the two largest military powers among the warring states, leading to the devastating Battle of Changping.

In 256 BC, a Qin general named Jiu (摎) attacked Han, killing 40,000 of the enemy and capturing Yangcheng (陽城) and Fushu (負黍).

During the times of King Geng Ding in late Shang dynasty (around 12th century BC), faced with a large Northern Di invasion, the aged Duke of Bin Gugong Danfu led his clan south and relocated to Qishan, and the Bin exodus resulted in the area being occupied by Di nomads hostile and stronger than Yiqu, who temporarily submitting to Xianyun (獫狁).

Yiqu took advantage of the chaos, rebelled and annexed the surrounding four smaller Xirong tribes, and established their own multi-city state centred around modern day Ning County, Gansu, spanning an area of nearly 100,000 square kilometres (39,000 sq mi) from Guyuan grasslands to the west, Qiaoshan to the east, Hetao to the north and Jing River to the south.

When King Ping moved east, a minor vassal lord from the land of Qinyi (秦邑), Duke Xiang, provided military escort.

In 651 BC, one of the other larger Xirong tribes, Mianzhu, recruited a Jin man in exile named You Yu (由余) as the ambassador to Qin in order to improve the strained diplomatic relationship.

Knowing Qin could not focus on eradicating Yiqu when it had the hostile eastern states to deal with, and her son's rule was still shaky due to numerous rival princes keen to capture the throne, Queen Dowager Xuan decided to use an approach of pretended conciliation.

At the same time, King Zhaoxiang was aggressively acting to weaken rival warring states in the east and south, and Queen Dowager Xuan was secretly planning with her son the eventual annihilation of Yiqu.

Shortly after, the Qin army invaded and overran the leaderless Yiqu, permanently annexing its entire territory into the newly established commanderies of Longxi and Beidi (北地).

Thanks to the pleas of the concubine, Lord Mengchang was released within two days, and he quickly smuggled himself out of Qin, narrowly evading a small army that King Zhaoxiang had ordered to pursue him.

The allied army managed to penetrate past the Hangu Pass all the way to Yanshi (盐氏), forcing Qin to negotiate an armistice that involved returning the previously occupied Fengling and Wusui back to Wei and Han.

Over 70 cities were captured within six months, including its capital Linzi (臨淄), leading to the murder of King Min of Qi by his supposed Chu ally.

Qi eventually defeated the allied forces and recaptured lost lands after a routing victory at Jimo by Tian Dan using flaming oxen.

Zhao Kuo, an arrogant young man with great philosophical knowledge of military strategies but no real combat experience, immediately reversed all of Lian Po's strategic arrangements upon arriving at the frontline.

The young King Huan decided to assert his authority as the lord paramount and personally led an expedition in 707 BC to punish on the state of Zheng, but was badly defeated in the Battle of Xuge.

This destroyed any remaining prestige and authority the Eastern Zhou royal court had over its vassals, and confirmed the de facto independence of the feudal states.

However, the combined forces of this alliance was destroyed at Yique by the young Qin general Bai Qi, with 240,000 men killed and their commander Gongsun Xi (公孫喜) captured and executed.