得陇望蜀 — “To be insatiably greedy”

During the early Eastern Han Dynasty, regional warlords Wei Xiao controlled the Long region (present-day Gansu), and Gongsun Shu held the Shu region (present-day Sichuan), both declaring themselves kings and forming an alliance against the imperial court.

In the eighth year of Jianwu (AD 32), Emperor Guangwu, Liu Xiu, along with his general Cen Peng, led an army to conquer Tianshui (now part of Gansu Province). Cen Peng and another general, Wu Han, then encircled Wei Xiao in Xicheng.

Gongsun Shu dispatched troops to aid Wei Xiao, stationing them in Shangbang. Liu Xiu then sent generals Gai Yan and Geng Bian to besiege Gongsun Shu's relief forces, while he himself returned to the capital.

From the capital, Liu Xiu wrote a letter to Cen Peng, stating: "Once these two cities are captured, you may lead your troops south to defeat the Shu 'barbarians.' If a person is not content, even after pacifying Long, he will still long for Shu."

This line expressed the strategic idea of not being satisfied with merely controlling Long, but to immediately proceed to conquer Shu.

Later, the phrase '平陇，复望蜀' (pacify Long, then long for Shu) evolved into the idiom '得陇望蜀', which took on the meaning of being insatiably greedy and never satisfied with what one has, always wanting more.