History must be rewrite bcoz bharat varsh which includes Afghan, tibet, srilankha, half of the myanmar these are borders. Whatever he said in that book only pointing modern day bihar, uttarpradesh, bengal.
We have famous quote in Tamil "Then naadu oodaiya sivane potri ennatavarukum eraiva potri". Which means Siva owns that land or king and the head person who also the God for all.
Also verify the oldest temple near Rameshwaram called uthira kosha mangai (map). Which was even older than ramayana era. Where only two graha s (chandra and surya) for worship.
Which is scientifically denotes temple was designed before exploring of other planets by epic scholars.
Pasupathi nath symbol of indus valley civilisation having much more similarities
Between sivakalai and keeladi excavation sites.
Notably the bull which denoted in indus valley civilisation exactly matches kangeyam bull of Tamil nadu.
Here, naga's depicted as extremists and nearly a villian.
Naga's are largest tribal community in northeastern part of our country. They were traded their goods like scented flowers, emerald, honey, snake poison, animal skin, weapons, rare medicinal plants.
There is difference in reality and story.
We should analyse all the sources, we can't write a book as like that or by grandma stories or tv serials.
One of the tamil epic says that Naga's are hunting tribes who trades and exchanges their goods and get pearls, nutshell bangles, ivory, coconuts, médicinal spices, metalised weapon, cloth from southern traders of pompuhar( oldest port city which submerged under sea) Also says that traders goes from south by sea route bcoz nagas are not well good in shipping and navigation.
Check cilapathikaaram, seevagasithaamani, Google map- modern pompuhar.
These epics were written later Buddha era.
Author focused only certain places of Bharatha varsh.
There is a negligence.
Author trying to prove story as history.
Author must study all possible links of shiva before writing it.
According to my view, 80%percent of story belongs grandma stories, 20% are acceptable history.