List of heads of state of Florence
The first de facto Lord (Italian: Signore) in the history of the Republic of Florence was Cosimo de' Medici. Thanks to his moderate policy, Cosimo managed to maintain power for over thirty years until his death, ruling the state silently through his trusted men and thus allowing the consolidation of his family, the Medici, in the government of Florence.
Source: Wikipedia — List of heads of state of Florence (CC BY-SA 4.0)