Dridhrashtra and Pandu and their sons Pandavas and Kauravas.

Visithraveerya had died without leaving any children and as Bheeshma  also refused to rule the country,  Satyavati called her son sage Vyasa to come and have children through her daughter-in-laws and they have delivered two sons Dridhrashtra and Pandu. As Dridhrashtra was born blind he could not rule the country  and hence Pandu was made the king and he ruled Hastinapura.

One day when he was hunting in the Jungle he heard the sound from a bush and thinking that there were Deers playing he shot at that place with an arrow which killed a sage and his wife who were courting relationship. Pandu found to his horror the dying sage and his wife and went and asked for their forgiveness.Before his death the sage cursed the king Pandu that if ever he indulged in courtship with his wife he would die  immediately. Because of this curse Pandu went to the forest and lived there with his two wives, Kunti and Madhuri. His wives delivered five sons. Kunti delivered  Udhishtra, Bheem and Arjun and Madhuri his second wife,Nakul and Sahadev. 

Pandu  one day indulged in courtship with Madhuri, his second wife, forgetting about the curse and died there itself. Madhuri also died because she was the cause of her husband’s death. Kunti took the boys to Bheeshma when they learnt all the Vedhas and other martial arts and attained their bachelorhood.Bheeshma and Drona trained and taught these young boys all the martial arts and made them great warriors but Pandavas were much better in all arts and this made the Kauravas jealous who tried to undermine the valour of Bheem and Arjun and many times tried to kill them. When the Pandavas joined their Kaurava cousins and moved with them the Kauravas were jealous of them because the Pandavas were superior in all arts, archery, martial games and vedhas etc. So they gave them trouble and hatched many schemes to kill them. But the Pandavas survived.

As Dridhrashtra was ruling and Kauravas had an upper hand they refused to share power with the Pandavas and refused to yield. But Bheeshma calmed them and split the state into two and Pandavas ruled Indhraprastha and Kauravas Hastinapura.

Duryodhana the eldest son of Dridhrashtra wanted to vanquish the Pandavas and tried everything under his control to achieve this. He along with his uncle Sakuni. Sakuni the brother of his mother Gandhari , was against his sister marrying the blind Dridhrashtra but  could not stop the marriage of his sister and had come along with her to Hastinapura and lived there and spoiled Duryothana and made him an enemy of Pandavas.

As the Pandavas were famous and ruled their land well and were powerful   Sakuni and Duryodhna called the Pandavas for playing a chess game and defeated Udhishtra and took the kingdom and driven the Pandavas to Jungle for twelve years and one year live in  incognito and then claim back their land. If they fail in this they would forfeit their land for ever. So the Pandavas were driven to Jungle and later came back successfully completing their thirteen year jungle life and as Duryodhana refused to give back their country and hence Pandavas fought and defeated them.