By Keith Christiansen and Carlo Falciani The Medici family ruled Florence without interruption between 1434 and 1494, but following their return to power in 1512, Cosimo I de' Medici demonstrated an unprecedented ability to wield culture as a political tool. His rule transformed Florence into a dynastic duchy and give Florentine art the central position it has held ever since. As Florence underwent these dramatic political transformations in the sixteenth century, portraits became an essential m
