Cao Cao, whose zone of control was the precursor to the state of Cao Wei, had raised an army in 189. In several strategic movements and battles, he controlled Yan Province and defeated several factions of the Yellow Turban rebels. This earned him the aid of other local militaries controlled by Zhang Miao and Chen Gong, who joined his cause to create his first sizeable army. He continued the effort and absorbed approximately 300,000 Yellow Turban rebels into his army as well as a number of clan-based military groups from the eastern side of Qing Province.