[1] Tian Jian succeeded his father, King Xiang, who died in 265 BC.
[2] One famous anecdote is that after the Battle of Changping in 260 BC, in which, according to the historian Sima Qian, 450,000 soldiers of the state of Zhao were killed by the Qin army, King Jian was advised: "Zhao is a hedge that protects Qi... just as the lips protect the teeth.
"[3] However, the king did nothing; during his reign he tried to stay out of wars, as the future First Emperor Qin Shihuang attacked all the states around him.
King Jian and his prime minister Hou Sheng (后勝), a relation of Jian's wife, sent the Qi army to the western border of Qi to protect the country; but Qin general Wang Ben (王賁), son of Wang Jian, attacked Qi from the north instead and conquered it in 221 BC, completing Qin's unification of China.
Wang Mang proclaimed to have descended from Jian of Qi (through Tian An [zh] from the Eighteen Kingdoms).