At the end of the Spring and Autumn Period (春秋时期 chūn qiū shí qí) (771 to 476 BCE), Jian Gong of the Qi State (齐简公 qí jiǎn gōng)1 set his sights on conquering the Lu State (鲁国 lǔ guó). At this point in time, the Lu State was no match for the Qi State, if Qi's army ever reached their gates, Lu would fall.
After receiving word of the potential threat, a disciple of Confucius namded Zi Gong (子贡 zi gòng) analysed the situation and came to the conclusion that the only way Lu could survive an attack was if the Wu State (吴国 wú guó) stepped in to help.
As Zi Gong gathered information on Qi he quickly learned of an official within the Qi government, called Tian Chang (田常 tián cháng), that was planning to usurp his King and seize the throne for himself. Tian Chang had been slowly rising in the ranks, eradicating potential dissidents along the way.
Zi Gong reached out to Tian Chang and began advising him on how best to overthrow his King. "If Qi attacks Lu, Qi will win with ease. There will be few casualties. The current King's armies will grow in size, and those in power will gain more, making them even more difficult to overthrow in the future. But if you were able to persuade the King to attack Wu - a state that is stronger than Lu but that would still fall to Qi - it would not be such an easy victory. The armies of Qi would be thinned, putting Qi in a more vulnerable position, ripe for the picking."
Tian Chang couldn't hide his excitement at the idea of a weakened Qi. "But how can I persuade the King to attack Wu? The plans to attack Lu are already underway."