The Upanishads have long fascinated Indian and foreign thinkers alike. The rich abundance of thought, the profound knowledge of Truth and life, the mystical pronouncements about the Individual and World Soul have inspired many writers jikI philosophers. Hut it was almost in--variably the philosophical aspect of the Upanishads which attracted attention. The cultural aspect was lumped together with that of the preceding and succeeding eras. That the Upanishads were composed apart from the early Vedit literature and showed both continuation of and departure from its customs and practices was ignored altogether. The present work is invaluable as a sodo-cultura! study of the Upanishads providing a deep insight into the land, the political and social institutions, the economy, religious ideas and philosophical urges of the people. It is based entirely on the older Upanishads: Aitareya, Brhadaranyaka, Chandogya,Isa,Katha, Kaushtaki, Kena, Maitrayani, Mandukya, Mundaka, Prasna, Svetasvatara and Taittiriya. In this work the Upanishadic spirit is represented by thinkers like Satyakama Jabala who did not waver from truth about his doubtful parentage, Maitreyi who did not covet material wealth, Janaka, Ajatasatru and Asvapati devoted to the cause of learning, Gargi Vacaknavi daring to question the mighty sage Yajnavalkya and Uddalaka Aruni ever on the move in quest of Truth.