Three thousand years of a trivium, wherein comes the name. From archives of the early 1300s, the dawn of the fortune of the Medici family, to which the most visible and celebrated part of Trebbio is still linked today, the name Trebio appears. Inventories, hitherto unpublished acts of notaries and minute study in the recesses of the castle now made it possible to determine the phases of construction prior to Michelozzo, clarifying Vasari's cryptic comment: "E al Trebbio medesimamente fece, come si vede, molti altri acconcimi" ("And to Trebbio likewise he made many other embellishments, as can be seen,"). For the first time we can measure the magnitude of Michellozzo's interventions in terms of innovation-conservation and their relevance to today of his refined design. From a complex reconstruction of the Medici genealogy, we were able to link Trebbio with the grand duke's branch of the family and offer glimpses of life in the villa at the time of the plague and city tensions.