Zhang Bao was a younger brother of Zhang Jiao and older brother of Zhang Liang. Zhang Bao was a general in the Yellow Turban Rebellion. He was defeated by the task force dispatched by the Han government, which included the generals Liu Bei and his brothers-in-arms Guan Yu and Zhang Fei.

After the death of Zhang Jiao, the Yellow Turbans lacked leadership and so crumbled into dust. It is said that Zhang Bao is the grandson of the founder of the Tianshi (Celestial Masters) Sect of Taoism, Zhang Daoling.

Zhang Bao was the middle out of his siblings, which included Zhang Liang, the youngest brother, and Zhang Jue, the eldest. After Zhang Jiao became proficient in the arts of magic, he taught his brothers what he knew, and in time, Zhang Bao himself could summon the wind and invoke the rain, and was just as knowledgable in the arts as his brothers. As time passed, Zhang Jue began to accumulate a large following, who were versed in the mystical arts as well. The following was named the Yellow Turbans.

Later Zhang Jue asked his brothers after the Yellow Turbans had ammased strength, "Popular support is the hardest thing to win. Today the people favor us. Why waste this chance to seize the realm for ourselves?" All three siblings agreed in moving against the Han, and so they had yellow banners made in preparation for the upcoming rebellion.

In years after, Zhang Bao was slain in betrayal by Yan Zheng, one of his own commanders. The Rebellion was quelled soon after.