I do not have any literature to give you but here is my opinion.

When whole terai was engulfed with the epidemic of Malaria only Terai basi's had resistance to malaria. Pahades were scared of Terai back then. Once there was cure to malaria it started attracting pahede people. Pahade people started migrating to Terai. Most pahades migrated to Terai and made their own space ( farm land) by deforesting the land. The royals and the kings awarded the open Tarai terain to their loyal pahedes and they became the new jamindaars. Those land were not cosficated from Terai people...those were either open terrain or deforested land that belonged to the state of Nepal.

So it just makes me laugh...when i hear a madhesi say " how did pahede take control of Tarai", as if it was stolen from Tarai people and handed over to pahedes.

The real natives of Tarai are tharus, rajbansis, Mia musalmans, dhimal were very little back then. They did their own farming and no one consficated their land. Yes there were cases where Chattu/cunning brahmins and chetris tricked some naive illiterate tharus and rajbansis into selling their land.

As life in Tarai became more and more easier than the hill more and more people migrated to Tarai....( citizens are free to move from one place to another)

What amazes me about people like Nagarikreport is that, they seek equal oppurtunity and rights for an Indian who immigrated to Nepal some 15 years ago by calling them a Terai basi but when it comes to a pahede who migrated to Tarai three generations ago, the pahade is taking over the Tarai????