The Niccolini-Cowper Madonna by Cowper, 6th Earl Cowper, George Augustus Frederick, Clavering Cowper, 4th Earl Cowper, George Augustus, The A.W. Mellon Educational and Charitable Trust, Johann Zoffany, Andrew W. Mellon, Niccolini, Raphael, Cowper, Countess Cowper, Katrine Cecilia Comptom, Clavering Cowper, 3rd Earl Cowper, George Nassau, Cowper, Francis Thomas de Grey, 7th earl Cowper and 7th baron Lucas, Desborough, Ethel, Lady, Inc. Duveen Brothers, Clavering Cowper, 5th Earl Cowper, Peter Leopold Louis Francis Nassau