This article examines Ottoman–Portuguese commercial agreements in Basra during the century after 1622 and the legal ambiguities that they engendered. On two separate occasions, the Portuguese established a factory in Basra: first in 1624 during the reign of the Afrāsiāb pasha (who governed in the name of the Ottomans from 1612 to 1667) and once again in 1690 when the city was ruled again by Ottoman governors (Ottoman direct rule was restored in 1667). Yet there were myriad issues that supplied cause for disputation between the two parties, not least the legal status of the factory itself. On the face of it, both the Portuguese and the Ottoman functionaries in Basra operated according to divergent models of extraterritorial trading privileges. After a century of expansion on the coasts of Africa and the Indian Ocean, the Portuguese had grown accustomed to the model of the factory (feitoria), in both those places in which the Portuguese governed in their own name and those in which they traded at the sufferance of African and Asian rulers. On the other hand, over the course of the sixteenth and seventeenth centuries, the Ottomans had granted so-called capitulations to European powers in the Mediterranean, which were governed by norms that were distinct from the factory model of Africa and Asia. Basra brought these two models into interaction and disrupted the straightforward implementation of either model. Frequent moments of misunderstanding and manoeuvring between the two sides were the result.