Who is Hanuman from The Bhagavad Gita and what is their importance?

Hanuman is a folk hero also known as a god, or as the king of the monkeys. "Hanuman the monkey god" appears on the ensignia of Arjuna in the war. Within the context of time, Hanuman has not existed forever, but emerged within India a few hundred years before the story in the Bhagavadgita.