In nineteenth-century Europe, groundbreaking technological progress was made in the field of maritime transport and aids to navigation. Already in the mid-19th century the French government, like other European authorities acting in their own economic and political interests, assisted its investors in obtaining important concessions for investments mainly in the field of public infrastructure in the Ottoman Empire, during the Tanzimat (Reform) period of modernization and westernization. The building and operation of the lighthouse network of the declining Empire is identified with the oldest major French company, Société Collas et Michel, which ran the Administration Générale des Phares de l’Empire Ottoman. At the crossroads of the developing Mediterranean sea-routes, on the island of Crete, then a remote dominion of the Empire, a series of lighthouses were constructed or modernized from 1864 to 1904. This article traces the history of this business venture, as it is reconstructed through the study of the archives of the Administration Générale des Phares de l’Empire Ottoman, currently held at the Archives Nationales d’Outre-Mer in Aix-en Provence, France; most importantly, it outlines the history and architecture of the lighthouse network of the island, and explores construction methods and materials, through in situ and archival research.