The film opens with Emperor Chandragupta Maurya giving away all his material possessions and taking a Sanyas. His grandson, prince Asoka, claims his grandfather's sword. The emperor explains that the sword is in fact a demon that, whenever unsheathed, craves blood without regard to friend or foe. He throws away the sword, but the prince recovers and unsheathes it whereupon it (accidentally) slashes a couple of birds on a tree.The film then takes us a few years ahead. Prince Asoka (Shahrukh Khan), now a brave youth, is battling the chief of Takshila. His general informs him that reinforcements have not arrived. Asoka figures out that his half-brother Susima (Ajith Kumar) has deliberately withheld them but, despite that, he wins using shrewd guerrilla tactics to defeat the enemy. Asoka identifies readily with harsh battle conditions and derives pleasure from victory and death to his enemies.Upon Asoka's victorious return to Magadha, a second attempt is made on his life, but he survives and challenges one of his stepbrothers to a duel in the arena. Before the duel, Asoka's mother, Queen Dharma, compels the prince to renounce his right and leave the kingdom to lead the life of a common man. The brave prince is naturally disappointed, but he accedes to his mother's wishes and leaves.In his travels, Asoka meets a lovely maiden Kaurwaki (Kareena Kapoor) and falls in love with her. Soldiers from the neighboring kingdom of Kalinga are chasing her and her little brother Arya. They are on the run along with their faithful general Bheema (Rahul Dev). After saving their lives, Asoka introduces himself as Pawan thus hiding his true identity. Kaurwaki and Arya are the princess and prince of Kalinga, who fled from their kingdom when the Prime Minister assassinated their parents.Asoka and Kaurwaki get married, but their union is short lived as Asoka receives word that his mother is unwell. He rushes to Magadha only to find that his mother is quite well and has discovered the conspiracy to remove him from power. The King dispatches Asoka to quell a rebellion in Ujjain. Asoka obeys but first returns to find Kaurwaki. Not able to find her, and not knowing she has gone into hiding, he is informed by Bheema that they were slaughtered and shows him the remains of someone else instead. A heartbroken Asoka attempts suicide, but is saved by Viraat (Danny Denzongpa), who on learning his true identity swears to protect him from all threats.Mad with grief and anger, Asoka embarks on a violent campaign of conquest to seek death. He fights with cold-blooded rage and without desire for his own life yet wins one battle after the next. News of his exploits travels to Magadha and Susima sends soldiers to assassinate him fearing that Asoka's popularity might cost him the throne. However, Asoka is saved in the nick of time by Viraat and taken to a Buddhist monastery to recover.There he meets a Buddhist maiden, Devi (Hrishita Bhatt), who cares for him. Even here, Susima's spies attempt to assassinate Asoka. In an attempt, Devi accidentally kills the assassin, and in Buddhist tradition, no one will now accept Devi as a wife. Asoka marries Devi in return and returns in splendor to Magadha.At this point, Susima and his brothers are wild with anger regarding their futile attempts to eliminate Asoka. They make their last political move, bribing the court astrologer to murder Devi (pregnant with Asoka's child now). The plot fails and Queen Dharma is killed instead. Asoka, now angered beyond measure, kills Susima and all his half-brothers (except Sugrata, who escapes and seeks asylum in Kalinga). Asoka is anointed Emperor but carries the title of Chanda Asoka (Brutal Asoka). Meanwhile, Devi, bent on swaying Asoka to peaceful ways, is shocked at this unbridled brutality and keeps on pushing him to adopt a gentler path.A few months later, Princess Kaurwaki and Prince Arya return to Kalinga with Bheema and through a dramatic turn of events, have the Prime Minister executed for treason. Prince Arya ascends the throne, but the celebrations are short-lived as Asoka declares war on the kingdom after they give shelter to his half-brother Sugrata. Kaurwaki still does not know that Asoka is Pawan, and they prepare for war.Consumed with rage toward Sugrata and Kalinga, Asoka nearly kills Viraat who begs him to stop the carnage and a terrible war is fought in Kalinga. The Magadha army suffers defeat initially, but the tide turns, and the Magadha army inflicts a cruel defeat on Kalinga. Not content with mere victory, Asoka's warriors raze everything and butcher everyone in sight. Sugrata is slain, as is Bheema, while Kaurwaki is wounded.In his chambers that evening, Asoka is informed by his brother Vitasoka (Madhu Varshitt), who has taken up Buddhism, that Devi has delivered twins, Mahindra and Sanghamitra. Asoka visits the scene of the battlefield, where he suddenly discovers his horse who was supposed to be in Kaurwaki's possession. With a sudden surge of hope, he frantically searches for Kaurwaki.Asoka manages to find her in the battlefield where he has a heart-to-heart talk. He apologizes deeply for his actions but is interrupted by prince Arya who is dying after being shot by several arrows. With Arya dying in his arms, Asoka suddenly finds his victory empty. In his attempt to fulfill his goals, he realizes that he only managed to be surrounded with more death. His enemies, his family, and even Arya, all dead, because of him. His grandfather's advice (about the sword) was right.The film ends with Asoka throwing the sword at the same spot his grandfather had thrown it and embracing Buddhism. The final narrative describes how Asoka not only built a large empire but spread Buddhism and the winds of peace through it.