Hanuman was born to a vanara couple Anjana, Kesari, in Mula Nakshatra, on the full moon day in the month of Chaitra. According to the Vedas, his mother Anjana was an apsara who, due to a curse, was born on Bhuloka (Earth) as a female vanara. She would be redeemed from this curse on her giving birth to an incarnation of Lord Shiva, who is also known as Rudra, that is also endowed with the Supreme Power of exalted devotion to Bhagwaan Hari. Hanuman is endowed with 28 transcendental divine opulences, with perfection in each. He is especially so because he is born with the Power of Rudra and with servitorship-devotion.
Along with Kesari, her husband, Anjana performed intense prayers to Shiva to beget Him as her Child. Pleased with their devotion, Shiva granted them the boon they sought. Hence, Hanuman is also known as "Maharudra" because he was born of the boon given to Anjana by Shiva.
Several different traditions account for Hanuman's birth. One is that at the time that Anjana was worshipping Lord Shiva, elsewhere, Dasharatha, the king of Ayodhya, was performing the Putrakama Yagna in order to have children. As a result, he received some sacred pudding, payasam, to be shared by his three wives, leading to the births of Rama, Lakshmana, Bharata, and Shatrughna. By divine ordinance, a kite snatched a fragment of that pudding and dropped it while flying over the forest where Anjana was engaged in worship. Vayu, the Hindu deity of the wind, delivered the falling pudding to the outstretched hands of Anjana, who consumed it. Hanuman was born to her as a result, Being Anjana's son, Hanuman is also called Anjaneya which literally means "arising from Anjani".