When the Dutch Republic and the Ottoman Empire established formal relations in 1612, they committed themselves to maintaining friendly diplomatic relations as well as commercial ones. Seventeenth-century Dutch diplomacy in Istanbul revolved around Dutch trade, especially in Izmir. Ottoman cultivation of the Dutch served mainly international strategic purposes, for their role in which the Dutch received unusually benign Ottoman treatment. Formal diplomacy aside, relations between these states and their subjects materialized in the everyday contact between Turks, Franks, Latins, Greeks, Armenians and Jews in Izmir. The development of that city peaked during the pivotal years 1675-1678. In these mere four years a confluence of administrative, commercial, and international political developments transformed the Dutch nation of Izmir from a collective of smuggling freebooters into a discrete professional community. As such, these years are an endpoint as well as a starting point in Ottoman-Dutch relations: they mark the shift of the primacy of the Dutch Levant trade in a Mediterranean mould, towards the primacy of professional Dutch international diplomacy.