A brief summary of the state of early Indian history
For a moment let us set archaeology aside and examine what textual evidence is available for the dates in early Hindu history.
Generally people accept the following relative chronology:
-Early/middle layers of the R^igveda, parts of the atharva veda.
-Latest R^igveda, core atharva veda, core yajur veda
-Events of the rAmAyaNa
-vedAnga jyotiSha, core events of mahAbhArata, late vedic material
-systematization of vedic saMhitas, shrauta rituals, janamejaya’s conquest of takshashila
-first purANas composed, end of vedic composition
-brahminical sutra literature begins
Other assumptions that generally may be accepted:
-based on their content it appears that the brAhmaNas/upaniShats were composed starting from the circum-rAmAyaNa period right down to the sutra period.
-many hindu texts are layered and mix compositions of different ages.
-Most of the records are pUru-centric, followed by ikshvAku, yadu, videha/kanyukubja. There were significant areas of Indo-Aryans who did not belong to this basic extended core. These included, for example haihaya yadus, some anu kingdoms, bR^ihadrathas, kAshis, pragjyotiShas.
Main inference that may be drawn regarding dates:
-In my examination both the epics while having several astronomical allusions represent mixed tradition. Hence it is obvious that one gets widely conflicting dates.
-However, the itihAsa and purANa tradition have memory of a very long standing series of monarchs amidst many Indo-Aryan dynasties: 80-95 generations from the start to the bhArata war. These lists are largely consistent across various purANas and epics, hence the lists of this size could not have been simply concocted. Hence, even with a conservative estimate about 1700 years had elapsed since the bhArata war to the start of Indian memory.
-In my opinion the best way of obtaining historical dates is by using astronomical data. We get one such anchor point in the form a series of hymns from the yajurvedic and and atharva vedic corpus in the form of the kR^ittika at 0 hr on Spring equinox. This constellation is very closely linked to some very basic vedic rituals and hence it is very contrived to imagine it as being a reminiscence. Also by the time of the vedAnga jyotiSha a change had occured in the 0hr and this was recognized. There are allusions to an earlier equinotical point in the rohiNi nakshatra. These facts have been known for more than 100 years now and its plain foolishness on the part of detractors to wish them away. If one were to believe them the Indo-Aryans only reminisced of the past but never composed anything regarding the present.
-From these observations one can calculate the sheet anchor kR^ittika date as being ~2200BC, that is the core yajur/atharvan period. The core yajur brAhmaNa portions were clearly after this period and contain mentions of kings corresponding to the bhArata war era, like vichitravIrya, dhR^itarAshTra and janamejaya. So the bhArata war was well after 2200BC. And based on the earlier astronomical allusions in the R^ig and brahminical genealogies the early phase of the R^ig can be placed around 3100 BC. Considering that some of the early kings in the purANic king lists such as mandhAtA, trasadasyu, purukutsa, mudgala, bhR^imyashva and vishvAmitra span a part of the early R^igvedic period one may fix the bhArata war era as definitely occurring after 2000BC and probably even after 1500 BC. The most plausible dates being between 1500-1000 BC. This also matches the paurANic testimony of the bhArata war relative to the nanda regime.
-If the Indus valley civilization had shown clear Hindu (Indo-Aryan) characteristics then one may have safely assumed that all this history played out entirely in Greater India, with a pre-R^igvedic, pre-IVC Indo-European invasion of India. However, this is not exactly the case and hence one is left with the invasion and Aryanization during the IVC as the best option.
-IVC archaeology is not really in an advanced state and hence not much can be made of the details from the existing information.
-So after all New Ayodhya, New Kanyakubja may not be far fetched.