Sometimes written 'Ajatasatru', translated from Sanskrit this name means 'enemy before birth'. This reading is primarily derived from the Pali version of the name, Ajatasattu. In all variations, the 'a' is long, and in the Sanskrit forms, the 's' is pronounced sh (Velthius Scheme Romanization: Pali: Ajaatasattu, Sanskrit: Ajaata'satru.
In the Pali Canon, the name Ajatashatru refers to the son of Bimbisara, king of Magadha. References are made to a prophecy, referring to strange behavior on the part of Ajatashatru's mother during her pregnancy (she wished to drink blood from her husband's knee (!?)), that was taken as a sign that Ajatashatru would kill his father in order to assume the throne.
Ambitious and eager to assume the throne, Ajatashatru indeed sought to kill his father, entering into a dark covenant with Devadatta, the wicked cousin of the Buddha. Each sought to advance through the death of another; Devadatta by killing the Buddha, and the prince by killing his own father.
The plans went forward, and the prince provided the assassins that Devadatta sent against the Buddha, as well as other methods for killing the Blessed One. None of the assassination attempts of the pair worked, and the plot was discovered before the attack on king Bimbisara could go forward.
Bimbisara, a devoted follower of the Buddha, sought to heal the break with his son, and so abdicated in his favor, making him the new king of Magadha. Ajatashatru was still not satisfied, however, and was troubled by thoughts that his father might someday attempt to regain control of the kingdom. He imprisoned Bimbisara and his wife, and starved him to death. And you think your kids cause trouble.
After assuming control of the kingdom, Ajatashatru was often troubled by the memory of the dark acts that he had committed in order to gain the throne. He often sought out the advice of various holy men and teachers, seeking advice on how to rule, and supported their activities through generous gifts in order to salve his own conscience.
After finding no peace in his discussions with various teachers, the young king sought out the Buddha, ostensibly to discuss the possibility of invading a nearby kingdom1. The Buddha responded that the king would be unable to conquer the nation in question, because it was united under democratic principles and a benevolent and just ruler. The Buddha also discussed the role of the Sangha as a supporter of a government that cared for and consulted its citizens.
Hearing these teachings, Ajatashatru was converted to the Buddha's teachings, and became a life-long supporter of the Sangha. He is said to have received a portion of the ashes and relics of the Buddha after his death, constructing a giant, ornate stupa to house them. He is also said to have built a large meeting hall for the first of the Buddhist Councils.
Ajatashatru's story, like that of Angulimala, is one of redemption, but it is tempered with concern for the consequences of ones actions (perhaps more so than the story of Angulimala). When Ajatashatru departed having heard the Buddha teach, the Buddha indicated to the assembled monks that while the king had gained some measure of insight and peace through hearing the Buddha speak, had it not been for the murder that he had committed, he would have been enlightened having heard the Buddha's teachings. Instead, upon his death, the king fell into Hell, where he was punished for the patricide that he had committed. Upon his release from Hell, Ajatashatru was born as a human, and gained enlightenment as a Pratyeka-buddha.
- The chronology of Ajatashatru's conversion seems to be a little confused. In several references I have seen, the discussion over the invasion of Vajji is said to be Ajatashatru's first encounter with the Buddha. In the Digha Nikaya, however, it appears that Ajatashatru takes refuge in the Buddha following a discussion of the fruits of the Holy life (DN 2), and later sends a messenger to inquire about the invasion of Vajji shortly before the death of the Buddha (DN 16).