Lady Margaret Butts by Hans Holbein, 1543. (Isabella Stewart Gardner Museum, Boston)

Sir William Butts by Hans Holbein, 1543. (Isabella Stewart Gardner Museum, Boston)

Joseph Munstermann by Hermann tom Ring, 1543. (Westfalisches Landesmuseum, Munster)

An Unknown Couple by Lorenzo Lotto, c.1543. (The Hermitage, St. Petersburg)

Sir Thomas Gresham by an artist of the Flemish School, 1544. (The Mercers' Company)

Laura da Pola by Lorenzo Lotto, 1544. (Pinacoteca di Brera, Milan)

An Unknown Man by Georg Pencz, 1544.

Eleanor of Toledo with her son Giovanni de' Medici by Agnolo Bronzino, c.1544-45. (Uffizi Gallery, Florence)

Cosimo I de' Medici by Agnolo Bronzino, 1545. (Uffizi Gallery, Florence)

An Unknown Child by a member of the Flemish School, c.1545-55. (Metropolitan Museum of Art, New York)

Don Carlos of Austria by Alonso Sanchez. (The Prado, Madrid)

Archbishop Cranmer by Gerlach Flicke, c.1545-46. (National Portrait Gallery, London)

Sir William Palmer by Gerlach Flicke, c.1546. (Private Collection)

An Unknown Florentine child by an artist of the Florentine School, c.1545-50. (National Portrait Gallery, London)

Emperor Charles V by Titian, 1548. (Prado, Madrid)

Sir Edward Seymour by an Unknown Artist. (National Portrait Gallery, London)

An Unknown Man by an Unknown Artist, c.1548. (The Royal Collection)

Thomas Wentworth, 1st Baron Wentworth attributed to John Bettes, 1549. (National Portrait Gallery, London)

Jeanne D'Albret, Queen of Navarre by an Unknown Artist, 1550.

Thomas Gresham by an Unknown Artist, c.1550. (Private Collection)

Eleanor of Toledo by Agnolo Bronzino, c. 1550, image provided by Jon. (Wallace Collection, London)

Eleanor of Toledo by an Unknown Artist, image provided by Jon.

Eleanor of Toledo by an Unknown Artist, image provided by Jon.

Eleanor of Toledo by Agnolo Bronzino, c. 1550, image provided by Jon.

An Unknown Lady by Agnolo Bronzino, c.1550.

Thought to Lady Jane Grey, previously identified as Mary I by Hans Eworth, c.1550-55. (Fitzwilliam Museum)

Ludovico Capponi by Agnolo Bronzino, 1551. (Frick Collection, New York)

Francesco I de' Medici by Agnolo Bronzino, 1551.

Catherine of Austria, Queen of Portugal by Antonio Mor, c.1552. (Prado, Madrid)

Laura Battiferri by Agnolo Bronzino, c.1555-60. (Palazzo Vechhio, Florence)