Sīmǎ Yì (司马懿), courtesy name Zhongda (仲逹) was a military strategist of the Kingdom of Wei. He was a descendent of the famous historian Sima Qian. At a young age, he was victorious at the Battle of Wuzhang Plain against the Shu army, which was led by the great strategist and rival of Sima Yi, Zhuge Liang. Cao Cao was impressed with Sima's plans and decided to make him his strategist. Later, Sima Yi developed many plans, one being the wave pincer. He used the tecnique of rolling heavy boulders off a cliff in order to crush enemy Shu soldiers. He also participated in the battles of Xuchang and Hei Fei. Sima Yi's grandson, Sima Yan, established the Jin Dynasty by usurping power from Wei and became Emperor Wu. Jin started the fall of the Three Kingdoms. It conquered the remaining Wu