Jayadratha was the son of Vridhakshtra, king of Sindhu (present day Pakistan) and was the brother in law of the Kaurava prince, Duryodhana. He had married Dushshala, the only daughter of Dhritarastra and Gandhari.
One day when the Pandavas were in their vanavaas, the brothers went into the forest to collect fruits,wood, roots etc. Seeing Draupadi alone and enamored by her beauty, Jayadratha approached her and proposed to marry her even after coming to know that she was the wife of the Pandavas. When she refused to comply, he took the hasty decision of abducting her and started moving towards Sindhu. The Pandavas in the meantime learnt of this ghastly act and came in for Draupadi's rescue. Bhima thrashes down Jayadratha but Draupadi prevents Bhima from killing him as she doesn’t want Dushshala to become a widow. Instead she requests that his head be shaved and he be set free so that he doesn’t dare ever commit an act of transgression against another woman.
To avenge his humiliation, Jayadratha conducts severe penance in order to please Lord Shiva, who granted him a boon in the form of a garland which will hold all the Pandavas at bay for one day. While this was not the boon that Jayadratha wanted, he accepted it nevertheless. Not satisfied, he went and prayed to his father Vridhakshtra who blesses him that whoever causes the head of Jayadratha to fall on the ground will be immediately killed by having his own head burst into a hundred pieces.
With these boons, Jayadratha was an able ally to the Kauravas when the Kurukshetra war began. Using the powers of his first boon, he managed to keep all the Pandavas at bay, except for Arjuna and his charioteer Krishna who were battling Trigartas elsewhere on the battlefield. On this day, Jayadratha waited for Arjuna’s son Abhimanyu to enter the Chakravyuha and then blocked the exit knowing fully well that the young warrior did not know how to exit the formation. He also prevented mighty Bhima along with his other brothers from entering the Chakravyuha for Abhimanyu's rescue. After being brutally and treacherously killed by the Kauravas, Jayadratha then goes on to kick the dead body of Abhimanyu and rejoices by dancing around it.
When Arjuna returns to the camp that evening and hears of his son’s death and the circumstances surrounding it, he becomes unconcious. Even Krishna could not check his tears, hearing about the death of his favourite Nephew. After gaining conciousness Arjuna vows to kill Jayadratha the very next day before sunset, failing which he would kill himself by entering into blazing fire along with his Gandiva. Hearing of this vow of Arjuna, Dronacharya arranges a complicated battle formation the next day to achieve two objectives, one was to protect Jayadratha and two was to enable Arjuna’s death which so far none of the Kaurava warriors had even gotten close to achieving in normal battle.
The next day, despite a full day of fierce fighting when Arjuna is unable to get to Jaydratha, Krishna realizes that he would need to resort to unconventional tactics to achieve this objective. Using his divine powers, Krishna masks the sun thus creating a solar eclipse in order to create the illusion of sunset. The entire Kaurava army rejoiced at the fact that they had managed to keep Jayadratha safe from Arjuna and also at the fact that Arjuna now would be forced to kill himself to follow his vow.
Elated, Jayadratha also appears in front of Arjuna and laughs at his defeat and starts dancing around joyously. At this moment, Krishna unmasks the sun and sun appears in the sky. Krishna points Jayadratha to Arjuna and reminds him of his vow. In order to prevent his head from falling to the ground, Krishna asks Arjuna to shoot cascading arrows in a sustained manner so that Jayadratha’s head is carried over from the battlefield in Kurukshetra and travels all over to the Himalyas such that it falls on the lap of his father Vridhakshtra who was meditating there.
Disturbed by the head falling on his lap, Jayadratha’s father gets up, the head drops to the ground and immediately Vridhakshtra’s head bursts into a hundred pieces thus fulfilling the boon that he had given his son years ago.