Dadhichi was a Vedic king, son of Atharvan, who turned a great Rishi. Dadhicha gave his bones to destroy Vritra, a brahmin, who became the head of the Asuras. Dadhichi, also known as Dadhyancha, is an important character in Hindu mythology.He was the one of the greatest devotees of Lord Shiva. It is believed that after Shiva had been separated from Shakti, he had kept himself all alone in a jungle and on an annual festival of Maha Shivratri, Lord Shiva had first time appeared in front of his devotees as rishi Dadhichi and his disciples were offering him prayers. He is revered amongst the greatest of sages and is portrayed as an example that no sacrifice is too great when the result is the good of the world. His bones are used as a symbol on India's highest award for gallantry "Param Vir Chakra" as "vajra". He was among one of the greatest among clan of bhrigus. He is credited with giving up his life in order to allow the Gods (Devatas) to make weapons from his bones to defeat the Demons (Asurs), recapture Heaven (Svargalok) and release all the world's water for all living beings.
Dadhichi was the son of sage Atharvan and his wife Chitti (Bhaagvat Puraan, 4/1). Atharvan who is also known as Bhrigu rishi (Manas putra of Brahma) attained the name the Atharvan as he authored ("Heard") Atharvaveda. Chitti was sage Kardam's daughter. Dadhichi's wife's name was Swarcha and his son was Pippalada rishi, a great sage himself, who is supposed to be associated with the Pippalada school of thought and associated with the origin of the Praśna Upanishad. He had established his ashram in Misrikh, in Naimisharanya near Lucknow, in the state of Uttar Pradesh, India.Naimisharanya has been cited in all of the puranas as the place of his ashram, where it is still in existence. The current place of Sabarmati Ashram in Ahemdabad, is also one of the ancient sites of his ashram. In the ancient times sages used to travel long distances, so may be he stayed near sabarmati river for some time. His name is seen to occur in the 1st mandala of Rigveda (Bhagavata Purana, Srimad Devi Bhagavatam and in the Puranas). He is said to be the forefather of many other great rishis and various clans, such as the Dadheech Brahmins / Shaiva Brahmins (Dynasty/clan) in India claim to be his descendants.
Dadhichi is believed to have authoured the famous composition of "Narayana Kavacham", which is a famous hymn in southern India and sung for power and peace. He was a passer-by of Madhuvidhya to ashvin kumars which he learned himself from others.