["Asia‐Pacific Economic History Review, EarlyView. ", "\nAbstract\nThis article re‐examines an economic treaty concluded between Spain and the Sulu Sultanate in 1836. Analysing the Tausug (Jawi) and Spanish treaty versions alongside archival sources from Spain, the Philippines, and England, it traces the impact of indigenous agency beyond the formal signatories on economic and political transformations. Exploring marginal groups, such as the Sama and Chinese, the study situates the treaty within a resurgent Sulu economy against the backdrop of declining Spanish control in the Philippines, thereby offering fresh insights into the role of diplomatic practices, negotiations, and regional networks in the commercial dynamics of Southeast Asia's ‘Sulu Zone’.\n"]