The book discusses the origin, development and application of the four well-known 'roots' of Islamic Law, namely the Qur'an, Sunnah, Ijma',and Qiyas. As it is meant to be a piece of fundamental research in its field, due attention has been paid in this study to intensive historical analysis rather than extensively covering authoritative opinions. This study is based mainly on the works of Malik, Abu Ysuf, al-Shaybani and al-Shaf'iī. The author has attempted a critical analysis of the legal problems discussed in the early manuals of Fiqh to trace the evolution of the four foundations of Islamic Law.