He Jin
In 189, Emperor Ling died. The General-in-Chief He Jin then summoned Ding Yuan into the capital Luoyang with his regional troops to assist in the power struggle against the eunuch faction. Before Ding Yuan arrived, however, the eunuchs assassinated He Jin. Dong Zhuo, a warlord from Liang Province (涼州; present-day western Gansu) who was also summoned by He Jin, arrived in Luoyang ahead of Ding Yuan and defeated the eunuchs, grasping military control of the capital. After Ding Yuan arrived, Dong Zhuo managed to buy over Lü Bu, who killed Ding Yuan and presented the latter's head to Dong Zhuo.