Veda Vyasa had appeared in Dwapar Yuga. He was the son of Maharshi Parashar and Satyawati then known as Matsyagandha. Vyasa was a partial incarnation of the God. Veda Vyasa effected a division of Vedas, created Puranas conceptualized history (Mahabharataa-which was actually jotted down by none other than Lord Ganesha.) He also established different faculties for teaching his disciples. Yet staying in his hermitage at the banks of the river Saraswati, he was not satisfied with his performance. Something was still writhing within his heart to come out. So he was feelling upset and was unable to find a reason for his dejection. Just then, Devarshi Narada arrived there, and saw that Mahatma Vyasa was upset. As nothing was concealed from Narada, he told him the reasons for his moroseness.
Narada told him that though he had created great epics, yet all of them lack a devotional description of God. That was why his soul was still writhing. Narada also suggested him to describe the glory of Hari, or neither his voice, nor his creation would ever get pure. Devarshi Narada then narrated the tale of God and the glory of His devotees to Vyasa and said, “O great soul, look at the effect of devotion and company of the pious people that I have become Devarshi from an ordinary son of a maid”
After the departure of Narada, Vyasa sat in meditation and experienced the illusion that caught the life. He also experienced devotion. Thus, his fresh experience led Veda Vyasa to create this great scripture. The virtues of God had such a strong attraction that, lured by them, even self- indulgent Shukdevi ran back from the jungles to his father and prayed to let him read that scripture.
Because of their link with Lord Sri Krishna, Suta narrates the stories of Pandavas, their heavenly departure, coronation of Parikshit, his all round victories etc. as per their sequences in Mahabharata. He also narrates the episodes of Ashwatthama the son of Guru Drona, worship of God by Kunti etc. and migration of Lord Krishna to Dwaraka.