Legal pluralism has increasingly become a characteristic feature of many postcolonial Muslim-majority countries where judges and courts are often faced with the simultaneous application and invocation of colonial laws, local customary or tribal laws, traditional or classical Islamic law(s), and international law. Modern trends in Islamic legal discourse exhibit their own variety of pluralisms and interpretive contestations. The central question explored in this dissertation is why and how do certain interpretations and discursive trends of Islamic law make their way into law and policy and not others? Using the case of Pakistan, I contend that the dominant interpretive trends of Shariah or Islamic law are determined by the prevailing ideological direction of judges and courts. The research is based on fieldwork in Pakistan, Federal Shariat Court and Supreme Court cases, and biographical details of judges. The dissertation advances the argument that judges strategically overcome regime pressure to eventually advance interpretations of Islamic law that favor their philosophical and jurisprudential goals by 1) appointing like-minded scholars as jurisconsults, amici and expert witnesses, 2) by citing and creatively interpreting selective textual sources of classic and modern Islamic jurisprudence, and 3), by delaying legal rulings until a favorable regime returns to power. Through a detailed historical-interpretive analysis of thirty cases, the study traces specific legal doctrines and modes of legal reasoning in areas of law that have historically been associated with Islamic law such as family laws and criminal laws, as well as in more secular areas of law such as administrative law and laws related banking, finance, trade and human rights. These cases were selected because they represent doctrinal shifts in the court’s understanding of Islamic law. My conclusion from the key findings is that the Federal Shariat Court eventually favored the traditional Hanafi approach in secular areas of law such as banking, finance, and trade but not in areas of law that have historically been associated with classic Islamic law the most such as family laws and criminal laws. In human rights related cases, the judges of the above-mentioned courts developed a legal framework of Siyasah Shariah (meaning Islamic governance) based on a creative interpretation of certain non-Hanafi classic Islamic juristic texts and sources. This framework of Siyasah Shariah allowed judges to make international human rights law justiciable in the national case law by proving its compatibility with the Shariah. Using these interpretive frameworks and strategies, the court’s authority has now expanded to include areas of law that were technically outside of its domain and jurisdiction.The study challenges the idea that Islamic law is a mere reflection of regime politics and that all debates are settled first in the political sphere before they are manifested in the legal outcomes. It also exemplifies an excellent case study for the phenomenon of judges incorporating non-state law into national policies, meaning law that is not made by the state e.g. Islamic law of banking, trade, finance which was first made by jurists independent of any state authority. It also makes contributions to the literature on authority in contemporary Islam.