Surviving sources trace the ruling house of Wei to the Zhou royalty: Gao, Duke of Bi, was a son of King Wen of Zhou. His descendants took their surname from his fief. After the destruction of Bi by the Xionites, Bi Wan escaped to Jin, where he became a courtier of Duke Xian's, accompanying his personal carriage. After a successful military expedition, Bi Wan was granted Wei, from which his own descendants then founded the house of Wei.
Jin's political structure was drastically changed after the slaughter of its ruling dynasty during and after the Li Ji Unrest. Afterwards, "Jin ha no princely house" and its political power diffused into extended relations of the ruling family, including the Wei. In the last years of the Spring and Autumn period, the founders of Wei, Zhao, and Han joined to attack and kill the dominant house of Zhi in 453, resulting in the partition of Jin. King Weilie of Zhou finally legitimized the situation in 403, when he elevated the three houses' heads to the rank of marquess.
Warring States Period
The state reached its apogee during the reigns of its first two rulers, Marquess Wen of Wei and Marquess Wu of Wei. The third ruler, King Hui of Wei, declared himself an independent sovereign and concentrated on economic developments, including irrigation projects at the Yellow River. Hui felt that Qin in the west was weak and their land a barren waste. He focused on conquering the well-settled eastern lands which were richer in known resources. However, a series of battles including the battle of Maling in 341 checked Wei's ambitions while Qin's expansion went largely unimpeded, boosting its economy and military strength. Early strengthening of the state of Wei resulted from adoption of Legalist reforms proposed by Li Kui.
Defeat
Wei eventually lost the western Hexi region, a strategic area of pastoral land on the west bank of the Yellow River between the border of modern-day Shanxi and Shaanxi, to Qin. Thereafter, it remained continuously at war with Qin, requiring the capital to be moved from Anyi to Daliang. Wei surrendered to Qin in 225, after the Qin general Wang Ben diverted the Yellow River into Daliang, destroying the capital in a flood.
Marquess Wu of Wei, personal name Ji, son of Marquess Wen,
King Hui of Wei, personal name Ying, son of Marquess Wu,
King Xiang of Wei, personal name Si or He, son of King Hui,
King Zhao of Wei, personal name Chi, son of King Xiang,
King Anxi of Wei,personal name Yu, son of King Zhao,
King Jingmin of Wei, personal name Zeng or Wu, son of King Anxi,
King Jia,, personal name Jia, son of King Jingmin,
According to Sima Qian's Records of the Grand Historian written in the 1st century, the list of rulers is slightly different: King Hui died in 335 and was succeeded by his son King Xiang in 334. King Xiang died in 319 and was succeeded by his son King Ai, who died in 296 and was succeeded by his son King Zhao. However, the majority of scholars and commentators believe that King Ai, whose personal name is not recorded, never existed. It seems that Sima Qian assigned the second part of the reign of King Hui to his son King Xiang and added King Ai to fill in the gap between 319 and 296. On the other hand, a minority of scholars believe King Ai did indeed exist.
According to the Han Feizi, King Anxi had a lover named Lord Longyang, with whom he enjoyed fishing. One day, Longyang began to weep. When questioned, Longyang said he saw his own future in how he had treated a fish. Happy to have the catch at first, Longyang had wanted to throw it back when he caught a better fish. He wept, "I am also a previously-caught fish! I will also be thrown back!" To show his fidelity to Longyang, the king declared that, "Anyone who dares to speak of other beauties will be executed along with his entire family".
