An interpretive translation by Sheikh Tosun Bayrak of "The Secret of Secrets" by Sheikh Abdul Qadir al-Jilani (1077–1166 CE), considered by many to be one of the greatest saints of Islam and the founder of the Qadiriyya order. This book, published in English for the first time, explains how the outward practices of Islam—prayer, fasting, zakat, and Hajj—contain a rich inner dimension that must be discovered and enjoyed if outward actions are to be performed in a manner pleasing to God. In doing so, the soul finds true peace, and spiritual life is fulfilled.