Photo DeAgostini Picture Library/Scala, Florence.

Photo Scala, Florence.

Photo Scala, Florence.

Photo Scala, Florence. Courtesy of the Ministero Beni e Att. Culturali.

Photo DeAgostini Picture Library/Scala, Florence.

Photo Scala, Florence. Courtesy of the Ministero Beni e Att. Culturali.

Photo Scala, Florence. Courtesy of the Ministero Beni e Att. Culturali.

Photo Scala, Florence.

Photo Scala, Florence.

Photo Scala, Florence. Courtesy of the Ministero Beni e Att. Culturali.

Photo Scala, Florence.

Photo Scala, Florence. Courtesy of the Ministero Beni e Att. Culturali.

Photo Scala, Florence. Courtesy of the Ministero Beni e Att. Culturali.

Photo Scala, Florence.

The Royal Collection © 2011 Her Majesty Queen Elizabeth II. Photo: The Bridgeman Art Library.

The Teyler Museum, Haarlem, The Netherlands.

Photo Scala, Florence.

Photo White Images/Scala, Florence.

Photo National Galleries of Scotland.

Photo The Bridgeman Art Library.