Composer of the second epic of India. The first epic is The Raamaayanam of Vaalmiiki.
Mahaabhaaratham was first composed by the sage Vyaasa and later was expanded by his disciples by adding various contextual discourses which themselves were believed to be of Vyaasa, rendered by him elsewhere on different occasions.
Vyaasa was the manifestation of Lord Vishnu himself.
Sathyavathi, the daughter of a king named Uparicharavasu,was given in adoption to a headman of a fisherman community whose name was Daasha. When she was maiden at Daasha's home, she was ordered to run a boat on the river Yamuna to carry over passers of the river.
Once a great sage Paraashara gifted her with a son while being carried over the river to the other side. The boy was born young, like many supernaturally born people of those days would naturally do. This son was none other than the great Vyaasa. His original name was Krishna, meaning blue or black, from his body color. Also known as Dvypaayana, born on an island in the river, it means. He became later known as Vyaasa (Vedavyaasa) , which means the editor or bifurcator of the veda into 4 different wings known presently as the Rigveda, The Yajurveda, The Saamaveda and The Atharvaveda. He was also the composer of 18 great books called Mahaapuraanas(mahaa=great, puraana=genesis) and 18 sub-books called upa-puraanas(upa=sub). His fame rests on the Mahaabhaaratham(comprising 18 volumes called parvas), Mahaabhaagavatham, one of the 18 mahaapuraanas( comprising 12 volumes called skandhas) and the philosophical compendium Brahma-soothra's. Unlike Raamaayanam, Mahaabhaaratham undertakes topics of philosophy at many an instance, though not so much as in his later work Bhaagavatham. The Bhaagavadgeetha(=lord's discourse) in the 6th parva is considered to be the essence of Indian philosophy in a nut shell. Another example is Sanatsujaatheeyam in 5th parva.Vyaasa himself appeared in the course of events of Mahaabhaaratham. He played a key role in the story. Soon after his birth, he retired to forests for penance, promising his mother that he would come whenever she thought of him. His mother called him to request him to beget sons from the wives Ambika and Ambaalika of his deceased cousin Vichithraveerya. He gifted one son to Ambika, but due to her closing her eyes from out of fear at the sight of the sage, the boy was born blind. Again, at the request of his mother, she gifted another son to Ambaalika. But this boy too, was born as white as pale, as his mother turned pale at the sight of the sage. His mother again asked to him give another son to Ambika. Vyaasa agreed but Ambika did not like to meet the sage for that purpose. She guised her servant woman as her herself and sent to await the sage. The servant woman served the sage with devotion thereby getting a son alright, but he was unfit to the crown due to his low birth. thus it was Vyaasa who revived the ending lineage of the kouravas.
Many a time, he appeared in the scene and guided the people as was necessary. At the beginning of the war, he asked Dhritharaashtra if he wanted to see the war by himself. As the blind king only wished to listen from someone, Vyaasa gifted Sanjaya with divine vision to be able to see things happening before and in absence at both the camps.
He later composed this great work in 3 years-and some believe-taking the services of Ganesha as his scribe. He taught the great book to his diciples and it was one of his diciples, vyshampaayana that retold the entire story to Janamejaya, at the latter's request and at vyaasa's accord, during the serpent sacrifice.
Vyaasa was considered to be the greatest teacher of his days. All the sages believed him as incarnation of vishnu himself. He was praised as Lord Brahma without the four faces, Lord Vishnu without the four hands and Lord Shiva without the third eye . He ia believed to be immortal. We often refer to an unoverridable ordinance as Vyaasa 's word. This itself shows the regard he enjoyed among the sages in this country of thought and penance!