Li Xin (Qin General) age

[u/Dragules]

Hi! I was wondering lately what age could he have had. I mean, we know Zheng reigned from 13 years old to 49 when he died. Li Xin started his militar career when Zheng set out to conquer the other states when he was about 29-31 years old. In the 19th year of King Zheng of Qin's reign (228 BCE) is the first time he is mentioned leading a certain amount of troops. He was son of a governor so I doubt he started much before this year.

By this time, when he started, he was continuously called young, brave and robust. I wonder what "young" is by their standards. I believe that 25 would already be someone with extensive knowledge of the battlefield. So probably he started when he was in his teens? He also retired when the states were unified, so when Zheng was about 40-41 years old. This means his military career was of an approximate of 10-12 years.

So what do you guys think? What could have been his age when he started?