Although a Brahmin lineage, this gotra is descended from Kshatriya prince of the Suryavansha dynasty who was the great grandson of legendary King Mandhatra. Mandhatra was killed by Lavanasura who was killed later by Rama's brother Shatrughna. This is one of ancient India's most prominent and famous lineages, having produced Rama and his 3 brothers (See Genealogy of Rama) and Yadava lineage from Ikshvaku King Haryaswa in which Krishna was born. Jayadratha of Mahabharata also belonged to solar line. The first notable king of the dynasty was Ikshvaku. Other Brahmin gotras from solar line are Vatula, Shatamarshana, Kutsa, Bhadrayana and Vishnuvriddha. Of these Kutsa and Shatamarshana also descend from King Mandhatra like Harita gotra and have either Mandhatra or his sons (Ambarish/Purukutsa) as part of their Pravaras. The Puranas, a series of Hindu mythological texts, document the story of this dynasty. Harita was separated from Ikshvaku by twenty-first generations. To this day, many Kshatriyas claim descent from the Suryavanshi dynasty to substantiate their claims to royalty.
Brahmins of the Harita gotra trace their lineage to the eponymous prince. While most Brahmins claim to be descended from ancient sages, those of the Harita gotra claim to be descended from Kshatriyas trained by the Brahmin Angirasa and hence they have full kshatriya qualities. This created, according to the Linga Purana, "Brahmins with the qualities of Kshatriyas". Harita lived around 500 BCE. Dharmsutra of Harita are dated to a period of c. 300 BCE.
This is recorded in the Hindu tradition in the Vishnu Purana:
Ambarishasya Mandhdtus tanayasya Yuvanasvah putro bhut tasmad Harito yato ngiraso Haritah. "The son of Ambarisha, son of Mandhatri was Yuvanasva From him sprang Harita from whom the Harita Angirases were descended."
and in the Linga Purana:
Harito Yuvanasvasya Harita yata atmajah ete hy Angirasah pakshe kshattropeta dvijatayah. "The son of Yuvanasva was Harita of whom the Haritash were sons". "They were on the side of Angiras twice born men." "Brahmans of Kshattriya lineage." 
and in the Vayu Purana:
The Pravara of this gotra, used in ceremonies to reference the ancestors of the participant Brahmin has 2 variations:
- K. Jamanadas (2007). Devadasis: Ancient to Modern. Kalpaz Publications. p. 64.
- Bella Vivante (1999). Women's Roles in Ancient Civilizations: A Reference Guide. Greenwood Press. p. 64.
- Classical Dictionary of Hindu Mythology and Religion, Geography, History, and Literature by John Dowson