During the 18th century, the Adriatic region became a crucial maritime and terrestrial imperial intersection, and represented a space where different trans-local and trans-imperial actors from both shores of the Mediterranean defined what territoriality and maritoriality were. A case in point was the coastal town of Ulcinj/Ülgün, located in Ottoman Albania. Situated in networks that extended to Tripoli, Tunis, and Algiers and immersed in persistent maritime activity in the Adriatic and beyond, Ulcinj troubled Venetian, Habsburg, Ottoman and Ragusan authorities. Given the geo-strategical importance of the Adriatic as a connecting sea between Central Europe, Africa and the Ottoman Mediterranean, Venice, Vienna, Istanbul and Ragusa cooperated and competed with Ulcinj’s trans-Adriatic network consisting of sea captains and Janissaries. These actors engaged in the lucrative grain, livestock and timber commerce, and were prone to use physical violence on the sea to defend this trade. Such a behavior pushed the imperial actors to negotiate their zones of maritime mobility and define their legal obligations between themselves. Relying on the correspondence between Venice, Vienna, Dubrovnik and Istanbul, the paper depicts how this trans-Adriatic story of Ulcinj spatially and diplomatically shaped the 18th-century Adriatic and the imperial metropoles. In addition to reconnecting these disconnected histories between the Ottoman Balkans and the Ottoman Maghreb, the paper illustrates that Ulcinj and the broader areas were one of the main producers of maritoriality in the Mediterranean. In doing so, the paper makes an important corrective to the tendency of seeing and analyzing the Adriatic exclusively through the lens of the euro-centric Empires.