RUDOLF WITTKOWER (1901-1971) was a German-American art historian. He was on the staff of the Warburg Institute, London, and became professor at the University of London. He then headed the Department of Fine Arts and Archaeology at Columbia. His highly original works in English include Architectural Principles in the Age of Humanism, Art and Architecture in Italy, 1600—1750, Essays in the History of Architecture, Essays in the History of Art, and Baroque Art: The Jesuit Contribution.

MARGOT WITTKOWER (1902-1995) was born in Berlin and established herself as an interior designer. After moving to London with her husband, she became an expert on neo-Palladian architecture. She collaborated on a number of books with her husband, including Born Under Saturn and The Divine Michelangelo.

JOSEPH CONNORS is past Director of the American Academy in Rome, and currently is Professor of Art History, Columbia University.