Source: here.
I believe that despite all the noise on the topics the purANas are at
this point more enlightening on certain points than all the archaeology
of the Indian subcontinent. In fact it appears important that the future
archaeological studies in India, if they occur at all, must keep in the
mind the Pauranic timelines for poorly known Hindu dynasties. At the
outset I must make it clear that some well-known dates contested
recently by Hindu historical revisionists are indeed correct. Where the
real revision of Hindu dates is required is of an earlier era. The
acceptable dates that I find emerging from the purANas are:
Western: Alexander of Macedon, the yavana invader of India= 356-323 BCE.
This date is important for it is indeed a sheet anchor intersection
between the neo-yavana world and the Hindu world.
Hindu: mahAvIra the founder of the jaina mata467 BCE
That is his entire life can be definitely mapped between this period.
gautama buddha452 BCE
chandragupta mauraya 288 BCE
The nandas of magadha were definitely a major imperial power in eastern
India at the time of the invasion of Alexander of Macedon. We can be
sure that they came to power at least by 334 BCE and were ousted by
chandragupta and kautilya at least by 312 BC.
However, there are corruptions in the purANas. The main amongst these concerns the rise of the neo-magadhan powerof bimbisAra and ajAtashatru. Obviously this event is well recorded in the bauddha associated vamsha-gAthas. But we also should recall that important Hindu source, oft neglected as fiction, namely the vAsavadatta romance. Based on this we might conclude that bimbisAra’s clan, whose founder was a minister of the bArhadrathas, came to power by murdering the king of that line, arimjaya. The pradyotas in contrast appear to have been rulers of avanti, and might have been late-surviving descendents of the haihayas. In time a descendent of ajAtashatru, udayin built the city of pATalIputra. So it is the reign of the bimbisAra dynasty that marks the so called “second urbanization of India”. We through hindu source pin this event of udayin’s rise with complete certainity between 450-390 BCE. This period indeed does correspond well to the archaeologically attested urbanization and iron smelting in the Magadhan region.
This then leads to the important point that most likely shishunAga, a minister of udayin, either overthrew him or son to seize the magadhan throne. Most likely he there after launched a great imperialist campaign of magadhan expansion, in which he conquered the ikShvAku-s, pradyota-s and vatsa-s. Thus we may picture the neo-magadhan expansion in the following stages: 1) rise under ajAtashatru 2) conquest of much of north eastern and central India under shishunAga 3) reassertion of realm under nandas 4) pan-Indian empire under chandragupta and ashokavardhana 5) last great revival through counter-Helenistic conquests under the brahminical rulers puShyamitra and agnimitra.