Bihar was part of bengal presidency till 1912, then Bihar and Orissa were created as separate provinces by British

After independence of India in 1947 sylhet district was seceded to East Pakistan and Assam became state of India in 1950

Arunachal Pradesh border Indian states of Assam and Nagaland also share international borders with Bhutan, Myanmar and China

After independence for the first time Andra state was created based on linguistic basis.