On 28 March 1659 Gabbriello Riccardi, the Marquis of Chianni and chief steward to the Grand-ducal court, signed the purchase contract for Palazzo Medici. Through this deed Riccardi also became the owner of three buildings adjacent to the palazzo, which also belonged to the Medici. The price agreed was forty thousand scudi.
By handing over the historic residence to Gabbriello Riccardi and his nephew Francesco, the designated heir, the Grand-duke Ferdinando II de’ Medici gave his leading court official special recognition and a mark of distinction among the Florentine aristocracy.

The Riccardi family soon left their mansion in Via Valfonda and moved into their new residence. The marquis Gabbriello immediately launched a series of renovations, extensions and internal decorations. These operations were guided by two general principles: the exterior was to respect the tradition imposed by the Renaissance style of the Medici edifice, while the interiors were to be adapted to the Baroque pomp which was in vogue at the time.
The architectural work extended over a span of sixty years, divided into four essential phases.