The documents preserved at the Archivio Proprio Giacomo Contarini, collected by the homonymous Venetian Senator (1536-1595), mirror the various offices he held during his life time: supervisor of fortifications and of their building-sites; member of the Senatorial Commission in charge of judging the submitted plans for the construction of the Ponte di Rialto in Venice; and Commissioner of the Arsenal of Venice, to cite only a few examples. Giacomo Contarini always took care to copy and collect relevant material and to supplement it with copies of treatises which could have been helpful in solving the concrete problems encountered in his professions. His maecenatism, which allowed him membership to the most important cultural circles of Venice and Padova, like the one gravitating around G. Pinelli, brought him in friendly and professional contact with figures like Palladio and Galileo. Evidence of these cultural interests can be found in his private Archive, especially concerning his interest in painting, poetry, Greek, philosophy, theology, botany, and mathematics. Microeconomic history, shipbuilding history, history of architecture, and thanks to Contarini's position, the contacts between this practical knowledge and the academic world, are the research fields in reference to which this collection best expresses its relevance.