Musta’man merchants were subjects of European nations operating within the Ottoman Empire who were provided safe passage and presence by the Porte through their holding of ahidnames. With the rights given by ahidnames, musta’man merchants were allowed to reside and trade within the Ottoman domains and to apply to Ottoman courts for litigation. While Venice and Genoa were the early beneficiaries of ahidnames, by the end of the 16th century France, England, and the Netherlands had strengthened their position in the Levantine markets by obtaining their own ahidnames. Musta’man merchants usually resolved internal disputes through the intermediation of their own consuls. However, according to the regulations stipulated in ahidnames, they were required to apply to the Ottoman courts for any disputes with Ottoman subjects. Examples of these cases may be found in Istanbul Sharia court records. A survey of 30 record books of Istanbul courts from the 17th century reveal that while 80% of the court appearances of the musta’man merchants were related to notary record keeping, 20%pertained to commercial litigation. Although most of the disputes were between musta’man merchants and Ottoman subjects, there were also examples of intra-musta’man litigation. Most of the records concerning musta’mans were related to credit relations, trade, taxation, and partnership issues. Moreover, suretyship and agency cases, which were required to be recorded in court, were also common. According to the ahidnames musta’man’s litigation with Ottoman subjects exceeding 4,000 akçes had to be adjudicated in the Imperial Council(Divan). However, many cases above 4,000 akçes were examined by local courts according to the Sharia and the stipulations delineated by ahidnames. In their Sharia court appearances, musta’man merchants frequently referred to ahidname articles about jurisdiction, documentary evidence, and special privileges. This gave them a clear advantage in their disputes with Ottoman subjects and often resulted in rulings in their favor. In addition, they supported their claims with fatwas from the office of the Grand Mufti. However, in maritime disputes, Ottoman judges occasionally appealed to maritime customs and provided solutions according to the customs of the musta’man merchants. The cases examined in this paper show that Ottoman judges were able to maintain their impartiality and protected the commercial activities of musta’man merchants, which would sometimes leave Ottoman subjects in less than favorable situations. Moreover, the Ottoman legal practices concerning the musta’man merchants was a synthesis of Sharia, in which ahidname stipulations and maritime customs displayed elements of legal pluralism