Origin of Maithil Brahamanas

Uttarakanda of Valmiki Ramayana  gives a detailed story of the origin of Maithil Brāhamanas.The King Nimi started a great yajna in which he invited rishi Vasiṣṭhafor performing this yajna. Vasiṣṭha accepted but was busy in another yajna for a long time and therefore could not come in time. In the meantime, King Nimi asked the rishi (sage) Gotama to perform the yajna.Mant other rishis were also invited. When Vasiṣṭha came and saw that the yajna was over, he cursed Nimi to live without body. Nimi retorted with a similar curse.By the blessings of his father Brahma, Vasiṣṭha was reborn in a kumbha (pitcher). Bhrigu and other sages asked the bodyless king Nimi whether he wanted to get a body, but Nimi refused and said he wanted to live in the 'pupils'(eyelids, Nimi) of people.Then Nimi's body was churned and a man was created, who came to be called Videha because he was born of a father who had no body (deha), and was also called Maithil because be was produced by churning (manthana).All the present gotras of Maithils are said to start from the sages who participated in the great yajna of Nimi.Yajnayalkya lived in Mithila (according to Brihadaranyaka Upanishada) and proponents of India's six philosophies also lived herew, including Gotama (Nyaya), Kapil(Samkhya),etc. Buddhism was widespread here.Later Udyotkata, Kumarila Bhatta, Mandana Mishra, Prabhakara, Udayanacharya, Gangesh, Pakshadhara Mishra, etc reestablished the Vedic religion by defeating Buddhists in debates. 

According to D.D. Kosāmbi, Śatpath Brāhmana tells that Māthava Videgha, led by his priest Gotama Rahugana, was the first king who originally lived in the land of Sarasvati crossed Sadānirā (supposed to be Gandaka) and founded a kingdom, where the people named videhas lived at the time of composition of Śatpath Brāhmana. Gotama Rahugana was a vedic rishi who composed many hymns of the first mandala of Rgveda. Most notable Rgvedic hymns of Gotama Rahugana are those which praise Sva-rājya, which was indisputably the State of Videgha which later became Videha due to phonetic change. Māthava Videgha, therefore, must belong to the Rgvedic period and must have preceded the period of Śatpath Brāhmana by a considerable gap. Rgveda also mentions hymns by Kāśirāja Pratardana in tenth mandala. Hence, Mithilā and Kāśhi formed part of the region in which Rgvedic peoples lived. Descendandants of Gotama Rahugana were called Gautama. One such sage lived near Ahilya-sthāna during the age of Rāmāyana.