1. Usul Ash-Shashi is an authoritative beginner's manual on the principles of Hanafi Usul al-Fiqh ( Principles of Islamic Jurisprudence)
2. It is used as a primary text in the curricula of Islamic schools and seminaries ever since it was written 800 years ago.
3. 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'  However this book is on the principles of Islamic Jurisprudence in the Hanafi school of law
4. A first time translation, with an easy to understand commentary interspersed within the text.
5. Includes the Arabic text.  

Four Fundamentals Sources of Islamic Shari' Law is Discussed in this book:

1. Qur'an 
2. Sunnat 
3. Ijma (consensus) and 
4. Qiyaas (Analogy)