The particular book tries to explore several facts regarding Adivasi politics and mobilization in colonial Chhotanagpur during the first half of the 20th century and recognizes its own historical importance and relevance which establishes the fact that the Adivasi Mahasabha, through its political discourses and participation and through the organizational set up, programmes and mobilization of Adivasis, recognized and established Adivasi identity. Adivasi Mahasabha became major socio-political and cultural front as well as a day to day movement for the Adivasis of Chhotanagpur region. There are some fundamental questions; mentioning here that if several Adivasi organizations such as Chhotanagpur Unnati Samaj, Chhotanagpur Catholic Sabha, Kishan Sabha, Munda Sabha and some others political front merged into Adivasi Mahasabha and accepted the secular mode of this particular organization then what was the actual reason behind the formation of Adivasi Sanatan Mahasabha? To what extent Christian Missionaries played a vital role in the making of Adivasi Mahasabha? How Adivasi Mahasabha mobilized the masses of Chhotanagpur and what tactics or programmes they used for channelizing the Adivasis of whole Chhotanagpur? How the leaders of Mahasabha indulged and participated in identity politics with Bihari Congressmen at the times of colonial Bihar? This particular book tries to find out the reasons that how and why Adivasi Mahasabha succeeded in mobilizing the Adivasi masses when there were very few transport facilities and the medium of information technology at that time. It also finds out the reason why the leadership of Adivasi Mahasabha was handed over to Jaipal Singh; why not the other Adivasi leader? What were historical importance of the 2nd Annual Session of Adivasi Mahasabha and its impact and role of Adivasi leadership in its success? How these Adivasi Conferences were conducted and how the opposition reacted and countered to it? What was the role of Adivasi women in the making of Adivasi Mahasabha and to what extent Adivasi women contributed in the success of these Adivasi conferences? How conflicts and controversies played important role among the Adivasis to unite and mobilize against the political opposition? This book reveals some interesting facts such as there were also some internal conflicts within Adivasi Mahasabha where several groups had their own political interests. Generally, we can categorise these conflicts into three major factions. First, it was the extremists who were against collaboration with any other political parties and they always wanted to be an independent or free from any political alliance. The second was those who wanted an alliance with Indian National Congress and majorly supported all congress initiatives. Third was the 'Sarna Adivasis' group who opposed the political agenda of Sanatan Adivasi Mahasabha but concerned only of Sarna Adivasis within Adivasi Mahasabha. Some other important internal rivalries, we can say it as controversy, were Jaipal Singh vs. Julius Tigga and Jaipal Singh vs. Justin Richard. These two internal rivalries were over after sometimes although it had changed Adivasi politics and defined the nature of the Adivasi movement in the long run. As Adivasi Mahasabha movement took a leap forward, some Adivasis also came forward to claim themselves as a true representative of the Adivasis of Chhotanagpur and challenged the leadership of the Mahasabha.