This is the Seventh Volume in the series Frontiers of Knowledge and is devoted to the study of leading Scheduled Castes spread over India. The institution of caste is as old as the Indian Civilization, it has both advantages and disadvantages, though disadvantages outweigh its advantages. There have been efforts since the times of Lord Buddha to eradicate the system. The pioneers of the Bhakti Movement in the 15th and 16th centuries and the leaders of the socio-religious reform movements in the 19th century made herculean endeavour to do away with the caste system. India after Independence, has adopted the British model of democracy, whose main objectives are to provide social, economic and political justice; equality of status as well as of opportunity; and assuring the dignity of the individual, During the last six decades, the Central and State Governments, through their successive plans, have striven to usher in an equitable and egalitarian social order, where caste distinctions have no place. It is hoped that the present work will be found useful by all sections of the people including students, researchers, teachers, social activists and political leaders. The Volume is divided into three sections. Section one deals with Historical Perspectives and discusses topics like caste and social stratification in Western society. Caste system and casteism in India and various social and political implications of the Indian caste system with particular reference to the problem of corruption and prospects of democracy. Section Two contains a survey of leading castes in India highlighting their origin, migration-patterns, family structure, social Setup, marriage, occupation and responses to social and political changes. Section Three carries a Selected Bibliography of the subject as it has developed during the last 150 years.