accompanied by an informative text that serves as a colourful introduction to a barely known region, linked to mainland India via the narrow 'chicken neck' corridor of Cooch Behar (with Bhutan to the north, Bangladesh to the south). From the Himalayas through the jungles to the fertile valleys of River Brahmaputra, the seven states of NE India are home to anthropologically/linguistically/culturally diverse peoples: Tibeto-Burmans, Austroasiatics, Indo-Aryans.
Yet the authors focus, quite understandably, on the unifying elements. Hence the topics visited: animistic-shamanistic Donyi-Polo (Sun-Moon) belief system, traces of solar and lunar cults (chapter 4), as well as religious syncretism (ch. 10); Christian missionary activities (ch. 11); ritualized dance traditions, festivals, etc. (ch. 7-8); material culture: tubular long-house structures (up to 90-m-long, ch. 5), textile and jewelry art (ch. 6); hunting, the significance of mithan buffalo, animal sacrifices (ch. 9, 11); megalith cultures (Khasis, Mizos, Nagas) related to ancestral worship, funerary rites, and fertility cults (ch. 12); tattooing and the once widespread practice of head-hunting (ch. 12); clannish or tribal societies where matrilineal descent is held in high esteem (Khasis, Jaintias, Garos, et al., ch. 13); the Hindu Tantric Mother Goddess Kamakshya/Kali's (blood) cult in Assam and vestiges of human sacrifices (pp. 159-63).
While there is no shortage of folkloric and mythological accounts, historical references are lot more sporadic. A brief overview concerning, say, the Ahom monarchy in Assam (1228-1826), the British (East India Company's) intrusion/colonization, ethnic or ideological insurgencies (especially since 1947), the border war between India and China in 1962 that affected NEFA/Arunachal Pradesh and occupied Tibet, would have been useful.
Corrigenda - Addendum:
+ The Chinese emperor Qin Shi Huangdi (of the Great Wall fame) ruled 221-210 BCE, not 7th c. AD (p. 27).
+ Gompa (Tib. dgon-pa) denotes monasteries, not temples (p. 109).
+ It's worth to note that the sky-ladder motif in connection with the ancestors of the Tibeto-Burman Akas (p. 27) can be found among other ethnicities, too. In (Old) Tibetan lore, for instance, it is called dmu/gnam skas/thag (heaven/sky ladder/rope) that was irrevocably severed by the "Sovereign Slain by Sword" (Tib. Gri-gum btsan-po) in a fatal duel.
A paper by Robbins Burling (University of Michigan), "The Tibeto-Burman Languages of Northeastern India" (1999) -- 7-9 years ago it was available online;
Ranju Bezbaruah - Priyam Goswami - Dipankar Banarjee (eds.), North East India: Interpretating the Sources of Its History 2008.