"From different parts of the universe there arrived great sages like Atri, Cyavana, Saradvan, Aristanemi, Bhrgu, Vasistha, Parasara, Visvamitra, Angira, Parasurama, Utathya, Indrapramada, Idhmavahu, Medhatithi, Devala, Arstisena, Bharadvaja, Gautama, Pippalada, Maitreya, Aurva, Kavasa, Kumbhayoni, Dvaipayana and the great personality Narada."

Srimad-Bhagavatam, 1:19:9-10

Cyavana: A great sage and one of the sons of Bhrgu Muni. He was born prematurely when his pregnant mother was kidnapped. Cyavana is one of the six sons of his father.

Bhrgu: When Brahmaji was performing a great sacrifice on behalf of Varuna, Maharsi Bhrgu was born from the sacrificial fire. He was a great sage, and his very dear wife was Puloma. He could travel in space like Durvasa, Narada and others, and he used to visit all the planets of the universe. Before the Battle of Kuruksetra, he tried to stop the battle. Sometimes he instructed Bharadvaja Muni about astronomical evolution, and he is the author of the great Bhrgu-samhita, the great astrological calculation. He explained how air, fire, water and earth are generated from ether. He explained how the air in the stomach works and regulates the intestines. As a great philosopher, he logically established the eternity of the living entity (Mahabharata). He was also a great anthropologist, and the theory of evolution was long ago explained by him. He was a scientific propounder of the four divisions and orders of human society known as the varnasrama institution. He converted the ksatriya king Vitahavya into a brahmana.

Vasistha: See Srimad-Bhagavatam 1.9.6.

Parasara: He is the grandson of Vasistha Muni and father of Vyasadeva. He is the son of Maharsi Sakti, and his mother's name was Adrsyati. He was in the womb of his mother when she was only twelve years old. And from within the womb of his mother he learned the Vedas. His father was killed by a demon, Kalmasapada, and to avenge this he wanted to annihilate the whole world. He was restrained, however, by his grandfather Vasistha. He then performed a Raksasa-killing yajna, but Maharsi Pulastya restrained him. He begot Vyasadeva, being attracted by Satyavati, who was to become the wife of Maharaja Santanu. By the blessings of Parasara, Satyavati became fragrant for miles. He was present also during the time of Bhisma's death. He was spiritual master of Maharaja Janaka and a great devotee of Lord Siva. He is the author of many Vedic scriptures and sociological directions.

Gadhi-suta, or Visvamitra: A great sage of austerity and mystic power. He is famous as Gadhi-suta because his father was Gadhi, a powerful king of the province of Kanyakubja (part of Uttara Pradesh). Although he was a ksatriya by birth, he became a brahmana in the very same body by the power of his spiritual achievements. He picked a quarrel with Vasistha Muni when he was a ksatriya king and performed a great sacrifice in cooperation with Maganga Muni and thus was able to vanquish the sons of Vasistha. He became a great yogi, and yet he failed to check his senses and thus was obliged to become the father of Sakuntala, the beauty queen of world history. Once, when he was a ksatriya king, he visited the hermitage of Vasistha Muni, and he was given a royal reception. Visvamitra wanted from Vasistha a cow named Nandini, and the Muni refused to deliver it. Visvamitra stole the cow, and thus there was a quarrel between the sage and the King. Visvamitra was defeated by the spiritual strength of Vasistha, and thus the King decided to become a brahmana. Before becoming a brahmana he underwent severe austerity on the bank of the Kausika. He was also one who tried to stop the Kuruksetra war.

Angira: He is one of the six mental sons of Brahma and the father of Brhaspati, the great learned priest of the demigods in the heavenly planets. He was born of the semen of Brahmaji given to a cinder of fire. Utathya and Samvarta are his sons. It is said that he is still performing austerity and chanting the holy name of the Lord at a place known as Alokananda on the banks of the Ganges.

Parasurama: See Srimad-Bhagavatam 1.9.6.

Utathya: One of the three sons of Maharsi Angira. He was the spiritual master of Maharaja Mandhata. He married Bhadra, the daughter of Soma (moon). Varuna kidnapped his wife Bhadra, and to retaliate the offense of the god of water, he drank all the water of the world.

Medhatithi: An old sage of yore. An assembly member of the heavenly King Indradeva. His son was Kanva Muni, who brought up Sakuntala in the forest. He was promoted to the heavenly planet by strictly following the principles of retired life (vanaprastha).

Devala: A great authority like Narada Muni and Vyasadeva. His good name is on the list of authorities mentioned in the Bhagavad-gita when Arjuna acknowledged Lord Krsna as the Supreme Personality of Godhead. He met Maharaja Yudhisthira after the Battle of Kuruksetra, and he was the elder brother of Dhaumya, the priest of the Pandava family. Like the ksatriyas, he also allowed his daughter to select her own husband in a svayamvara meeting, and at that ceremony all the bachelor sons of the rsis were invited. According to some, he is not Asita Devala.

Bharadvaja: See Srimad-Bhagavatam 1.9.6.

Gautama: One of the seven great sages of the universe. Saradvan Gautama was one of his sons. Persons in the Gautama-gotra (dynasty) today are either his family descendants or in his disciplic succession. The brahmanas who profess Gautama-gotra are generally family descendants, and the ksatriyas and vaisyas who profess Gautama-gotra are all in the line of his disciplic succession. He was the husband of the famous Ahalya who turned into stone when Indradeva, the King of the heaven, molested her. Ahalya was delivered by Lord Ramacandra. Gautama was the grandfather of Krpacarya, one of the heroes of the Battle of Kuruksetra.

Maitreya: A great rsi of yore. He was spiritual master of Vidura and a great religious authority. He advised Dhrtarastra to keep good relations with the Pandavas. Duryodhana disagreed and thus was cursed by him. He met Vyasadeva and had religious discourses with him.

Srimad-Bhagavatam, 1:19:9-10
Bhaktivedanta Book Trust. HDG A.C. Bhaktivedanta Swami Srila Prabhupada.