Usul Ash-Shashi is an authoritative beginner's manual on the principles of Islamic Jurisprudence. It is used as a primary text in the curricula of Islamic schools and seminaries ever since it was written 800 years ago, and yet, the author's profound humility prevented him from putting his name to the book. The first of the books written about the principles of Islamic Jurisprudence was that of Imam Muhammad Bin Idris Ash-Shafi'i (d204 H) which is known as 'Al-Risalah' so afterwards allot of books have been written on the subject by many scholars following the example of the Risalah.

One of those scholars who wrote on the principles of Islamic Jurisprudence in the Hanafi school of law was Imam Nidhamul Din Ash-Shashi, which is the most read and taught in the Hanafi school of law.