This book surveys the important works, both articles and books, of Wanand M. Callewaert, Professor Emeritus of Sanskrit and Hinduism at the KU Leuven, Belgium, done on Indian nirgun bhakti literature.

Containing some of his revised articles and summaries of books and articles published earlier, it focuses on Dadupanth, Namdev, Mirabai, Raidas, Guru Granth Sahib, Rancaritmanas, Kabir and Guru Nanakdeva. The devotional literature in South India and the Dictionary of Bhakti–North Indian bhakti texts into Khari boli Hindi and English–also find place in the discussion.