This article argues that the claims that international commercial adjudication is inconsistent with Islamic law, or, in the Arab context, is born out of the 20th century petroleum concession disputes, are unfounded. First, the early Arab-Islamic trade interactions, in their multicultural and legal contexts, established transnational commercial adjudication. These interactions were facilitated by flexible Islamic regulations regarding free trade and adjudication, especially the freedom to arbitrate. Second, there have been profound international and inter-Arab political contestations since the 1950s that have affected international arbitration. These contestations could render the petroleum disputes irrelevant to the evolution of Arab commercial adjudication and foreign investment arbitration. However, international arbitration can be traced back to the principle of due process of law beyond the State; the perceived founding principle of Arab commercial adjudication. Recognizing this history is important for researchers to assess the successes and flaws of arbitral due process in the Arab context.