Hanuman is an ardent devotee of Lord Rama and one of the central characters in the various versions of the epic Ramayana found in the Indian subcontinent and Southeast Asia. As one of the Chiranjivi, he is also mentioned in several other texts, such as the Mahabharata, the various Puranas and some Jain, Buddhist, and Sikh texts. Several later texts also present him as an incarnation of Shiva. Hanuman is the son of Anjana and Kesari and is also the son of the wind-god Vayu, who according to several stories, played a role in his birth.
Here’s how Hanuman got the name “Bajrangbali”.
After the Ram Rajya was established, once when Sita was applying vermilion (kumkum) to her forehead, a curious Hanuman asked her the reason for this. Sita explained that it was a ritual that would result in a longer and a healthier life for Ram. Enthusiast Hanuman, the as big a devotee of Lord Ram he was, went on and covered his entire body with kumkum and hence turned completely orange! Bajrang means orange and hence came the name: Bajrangbali!