Siena Cathedral is the product of a complex construction process that unfolded between the mid-13th and mid-14th centuries. The construction of the west front alone took at least three decades, from 1284 to 1317. Giovanni Pisano was the architect who designed the façade and supervised the construction work, but he was also the innovative sculptor who carved the statues for it now housed in the Museo dell'Opera.
A restoration campaign conducted from July 2005 to December 2006 provided an important opportunity for clarifying certain issues linked to the Cathedral's construction and for exploring the imposing façade in detail. Coming in the wake of the restoration of 2005–6, this book sets out to provide an exhaustive interpretation of Siena Cathedral's façade, its architecture, the inscriptions that abound on it, the sculptures adorning it and the mosaics embellishing it, right down to the history of the materials used to build it.