This book is a collection of ancient works related to the teachings of Siddha Yogis. We are pleased to present translations of traditional texts to anyone interested in the doctrine of tantric yoga. This book contains the works of the great teachers of antiquity - Matsyendranath and Gorakshanath, whose names are inextricably linked with the origin and development of the Nath Tradition. Among the many Sanskrit texts, there are not many works relevant to Natha Yoga. The reason for this could be the secrecy of the teachings and the transfer of knowledge using the language of symbols, understandable only to initiates.