Christian missions had a huge impact in the Northeastern region of India. This impact, combined with western (British) colonization, produced a synergy that changed the entire landscape of the Northeast. This dissertation focuses on the social and political aspects of that change. The primary catalyst was the translation of the Bible into local languages, and a highly successful education program that every mission and denomination implemented from the very beginning. That brought about an awakening and renewal of societies across the Northeast. The greatest change occurred within the tribal societies. It gave rise to a national identity movement, which continues to this day. This was aided by a stable British colonial administration, which provided the basic structure and framework for new tribal political states that would emerge decades later. New problems and challenges came with these changes. Foremost among them was the question of political sovereignty. Some tribal groups rose in rebellion against the national government of India and fought violent insurgent wars at various times. Some of those wars have come to a peaceful end, while others remain unresolved. The study also deals with the impact of Hindu religion and colonization in Northeast India, a process that was occurring long before Christian missions and western colonization made their appearance. This Hindu religious and cultural influence (called Sanskritization) had a serious negative impact upon certain tribal cultures, especially those in the Assam plains. It prevented growth and progress in their economy, education, social freedom, and political aspirations. In contrast, the Christian tribal societies have made impressive progress in all these areas. The Sanskritic-Hindu influence is still a potent force to deal with in the region. It is increasing under the current political climate in India. The Christians of the Northeast, particularly tribal Christians, need to be aware of the dangers confronting them and prepare themselves to face the new challenge by having a clearer understanding of the mission work in their homeland.