Born in Gwanghaeju (present-day Chuncheon), he became a general in the kingdom of Taebong.

He was instrumental in helping Wang Kŏn, who later founded the state of Goryeo to achieve power.

[1] Sin is remembered today for giving his life for Wang Kŏn in the aftermath of a rout of their forces by Later Baekje near present-day Daegu.

[2] According to the legend, the two exchanged armor so that the king would be able to escape the battlefield.

But eventually his army was routed and in the woods Sin was shot with arrows and was killed by the enemy.