Guan Ping

關平」

Was the first son of the famed 3rd century military general Guan Yu and elder brother of Guan Xing. He had served a military post under Liu Bei during the Three kingdom's era of China.

In the 14th century historical novel Romance of the Three Kindoms by Luo Guanzhong, Guan Ping was said to have been adopted by Guan Yu when he was seventeen (Chapter 28), as his true father requested to have him follow and assist the renowned general. Without a son then, Guan Yu took Guan Ping as his own.

source? wikipedia lah...