The aim of this book is to focus on the origin of the historiography of the terms Mannerism and Maniera in paintings and drawings of the sixteenth-century in Italy. The articles herewith presented fall into two categories. The first group explains the definition of the terms Mannerism and Maniera, their periodicity, and their sources as illustrated by Giorogio Vasari, John Shearman, Craig Hugh Smyth, and Sydney Freedberg. The second deals with the polemic associated with the usage of the term and historiography and its application as voiced by Walter Friedlaender, Max Dvorak, Ernst Gombrich, Henri Zerner, David Summers, Malcolm Campbell, and Iris Cheney.