The remarkable career of Francesco De Gratta (1613–1676) that began in the late 1640s, was inextricably correlated with the establishment of the early modern royal postal system in Gdańsk (the city fulfilled an important bridging role within the Poland-Lithuanian Commonwealth). The career followed distinct stages, tying Francesco De Gratta ever closer with the Crown, the nobility as well as the merchants in Gdańsk. It all started with his position as Head Postmaster in Gdańsk, in 1654. In 1661, he became Postmaster General of Royal Prussia, Courland, Semigallia and Livonia. After these initial steps, Francesco immersed in creditor activities and close contacts with the Royal Prussian cities, royal authorities, and not the least different Polish mint masters. This book details and analyses how De Gratta used his family as well as a number of executors and benefactors in his social and economic advancement. The study is based on various sources from a number of European archives and libraries, mainly those situated in Italy, Poland and Germany. Michał Salamonik is a historian working at the School of Historical and Contemporary Studies at Södertörns högskola (Södertörn University, Sweden).