An impenetrable obscurity settles on the Mauryan Empire after the reign of Asoka. The only certainty is that the great empire founded by Chandragupta and extended and maintained in all its splendour by his son and grandson did not long survive in its integrity. Tivara, the only son of Asoka named in his Inscriptions, is not heard of again.
The Pururujs, the Jain and Buddhist sources have different tales to tell, and later writers like Kalhana, the author of Rajatarangini, and Tibetan historian Taranath give their versions of what happened. It is impossible to construct a continuous history of the empire after Asoka. Perhaps after the death of Asoka in 233-32 B.C., the empire was divided into eastern and western parts.
The Puranas state that altogether nine Mauryan rulers ruled for 37 (B.C. 324-185) years. This may be true for Magadha but no list from other sources corresponds to these figures. Dasaratha is mentioned in the Parana list but is ignored by Jaina and Buddhist accounts. Dasaratha is, however, the only name borne out by epigraphy. Three Inscriptions relate his bestowing on the Ajivikas caves in the Nagarjuni Hills (near Barabar) immediately after his coronation. The Buddhist tradition mentions one
Samprati but the 3 ainas c\avm Yi’vm a CttWtft to their creed and say that he did as much for Jainism as Asoka for Buddhism. Samprati’s capital is given as Pataliputra by some and Ujjaini by others. Jalauka (or Jaluka), son of Asoka, is famous in Kashmir history as a propagator of Shaivism and persecutor of Buddhists.
According to Puranas, Salisuka succeeded Samprati. The Gargi Samhita states that his rule was very oppressive. Taranath mentions Virascna as ruling in Gandhara. He was probably of the same line as Subhagasena (Sophagasenus) of the Greek accounts.
There was evidently a division of the Mauryan empire and the north-western line of the Mauryas must have come to an end with the Greek conquest of the North-West, while the eastern line of Magadha may have held out somewhat longer till about 185-84 B.C.
When the last Mauryan ruler Brihadratha was overthrown and killed by the Maurya Commander-in-Chief Pusyamitra Sunga. Bana’s Harsha-charilra and Vishnu Purana both mention the treacherous assassination of Brihadratha. The fall of Brihadratha must be taken to mark the end of the Mauryan empire in 185-84 B.C.
Romilla Thapar after closely analysing the chronology of the Mauryan rulers after Asoka from various sources has come to the conclusion that after Asoka’s death, the Mauryan empire was partitioned into western and eastern halves.
The former was governed by Kunala, Samprati, etc. and later on this part was threatened by the Greeks from the north-west. In the eastern half of the empire, wilh the capital at Pataliputra, six latcr-Mauryan Kings, from Dasaratha to Brihadratha ruled. Thus the first three Mauryas ruled for 85 years and the later Mauryas, after Asoka’s death, for a total of 52 years. On the basis of this chronology the Mauryas ruled for 137 years.