The palace was designed by Michelozzo di Bartolomeo for Cosimo de' Medici, head of the Medici banking family, and was built between 1444 and 1484. It was well known for its stone masonry includes rustication and ashlar. The tripartite elevation used here expresses the Renaissance spirit of rationality, order, and classicism on human scale. This tripartite division is emphasized by horizontal stringcourses that divide the building into stories of decreasing height. The transition from the rusticated masonry of the ground floor to the more delicately refined stonework of the third floor makes the building seem lighter and taller as the eye moves upward to the massive cornice that caps and clearly defines the building's outline.