To Chinese minds, the "heqin" policy was humiliating and ran contrary to the Sinocentric world order like "a person hanging upside down", as the statesman Jia Yi (d. 169 BC) puts it. These sentiments manifested themselves in the Han court in the form of the pro-war faction, who advocated the reversal of Han's policy of appeasement. By the reign of Emperor Wu (r.141–87BC), the Han felt comfortable enough to go to war with the Xiongnu. After a botched attempt at luring the Xiongnu army into an ambush at the Battle of Mayi in 133 BC, the era of "heqin"-style appeasement was broken and the Han–Xiongnu War went into full swing.