The introduction of the Florentine gold florin in 1252 marked a pivotal moment in European and Mediterranean gold circulation, eventually establishing it as one of the dominant currencies of the late Middle Ages. While previous research has emphasized its role in long-distance trade from a macroeconomic perspective, this study shifts focus to its local and regional circulation within Florence and Tuscany. Drawing on primary sources from the Diplomatico collection of the State Archives of Florence (1252–94) and other archival materials, the chapter explores uses of the florin beyond international commerce, including loans, property transactions, and military expenditures. The analysis identifies two main phases: an initial period (1252–79), marked by scarce references and limited circulation, supporting claims of early unpopularity; and a later phase (1280–94), characterized by broader and more varied use, notably in military payments under the cavallata system and the emergence of a local lending market. The 1279 ordinance fixing the florin’s value would play a significant role in stabilizing the currency and encouraging domestic use. Ultimately, the chapter highlights intersections between macroeconomic forces and local practices, showing how political and military needs also shaped the florin’s internal adoption alongside its international role.