Deng Ai, a prominent general of the state of Cao Wei during the Three Kingdoms period, famously and secretly crossed Yinping Pass in 263 AD to launch a surprise raid on Chengdu, the capital of Shu Han. By bypassing the heavily fortified Jianmen Pass, where the main Shu army led by Jiang Wei was stationed, Deng Ai led his elite troops through nearly 350 kilometers of treacherous, uninhabited mountainous terrain. The journey was so perilous that soldiers reportedly had to wrap themselves in felt blankets and roll down steep precipices to descend. This daring maneuver allowed the Wei forces to emerge in the heart of Shu territory, quickly capturing Jiangyou and defeating Zhuge Zhan at Mianyang. The unexpected appearance of Deng Ai's army at the gates of Chengdu created such panic and despair that the Shu emperor, Liu Shan, surrendered without further resistance, effectively ending the state of Shu Han.