"An Introduction to Yoga" is a book written by Annie Besant, a prominent British social reformer, feminist, and spiritual teacher. The book provides a comprehensive guide to the philosophy and practice of yoga, with a focus on the principles of Raja Yoga. The book is divided into several chapters, each exploring different aspects of yoga, including the nature of the mind, the practice of concentration and meditation, the power of thought, and the attainment of spiritual consciousness. Besant provides clear and accessible explanations of these complex concepts, drawing on her own experiences as a practitioner of yoga and her extensive knowledge of Indian philosophy and spirituality. Besant's approach to yoga is grounded in a belief in the unity of all existence and the interconnectedness of all living beings. Moreover, "An Introduction to Yoga" is a valuable resource for anyone interested in learning more about the practice of yoga and its role in promoting physical, mental, and spiritual well-being.