Otto Naumann joined Sotheby’s in the summer of 2018 as Senior Vice President and Client Development Director in its Old Master Paintings Division. A celebrated scholar, earning his master’s degree from Columbia University and a doctorate in Art History from Yale, Naumann is renowned for his exceptional eye for quality and for determining difficult attributions. In 1981, he wrote the authoritative monograph on Frans van Mieris (1635 - 1681) and helped organize the 2005 exhibition on the artist at the Mauritshuis, The Hague and in the National Gallery of Art, Washington. Having made a name for himself specializing in Dutch and Flemish art, Mr. Naumann expanded the breadth of his trade in 2007 to include Italian, French, Spanish and British works as well as 19th century painting. He continues to pursue his academic work, currently working on a book on Rembrandt’s sketches.

Gary Schwartz was born in Brooklyn, New York in 1940. He studied Art History at New York University and Johns Hopkins University between 1956 and 1965. In 1965 he was granted a Kress Fellowship to the Netherlands, where he stayed. He has been active as a translator, editor and publisher; teacher, lecturer and writer; and as the founder of CODART, an international network organization for curators of Dutch and Flemish art. His publications on Rembrandt include Rembrandt: all the etchings in true size (1977), Rembrandt, his life, his paintings: a new biography (1984) and Rembrandt’s universe: his art, his life, his works (2006). Since 1995 he has been maintaining a blog, now named the Schwartzlist, free to subscribers.

Leonore van Sloten is curator at The Rembrandt House Museum in Amsterdam (NL). She studied Art History at the University of Amsterdam. Her master’s thesis focused on the written rules for making compositions in Dutch art treatises. Since 2005, she has curated numerous exhibitions, and published and produced publications on seventeenth-century art — with a special focus on Rembrandt and his school. Recent examples have been: Under the Spell of Hercules Segers. Rembrandt and the Moderns (2016), Ferdinand Bol and Govert Flinck: Rembrandt’s Master Pupils (2017/18) and Rembrandt Laboratory. Rembrandt's Technique Unravelled (2019) focused on new technical research on Rembrandt's artworks. Outside of her art historical work, Leonore is also active as professional classical singer, specializing in Romantic Lied repertoire and 17^th-century music.

Arthur K. Wheelock Jr. is Senior Advisor to The Leiden Collection. He recently retired as curator of Northern Baroque painting at the National Gallery of Art in Washington, D.C., and as Professor of Art History at the University of Maryland. During his tenure at the National Gallery from 1975 to 2018, Wheelock oversaw a significant expansion of the Gallery’s collection of Dutch and Flemish paintings and organized a number of major exhibitions. Wheelock has lectured widely on Dutch and Flemish art and has written many articles and books. His revised and expanded Dutch catalogue, which was published online in 2014, received the George Wittenborn Book Award as the best art publication in the United States for that year. In 1982, at the time of the Dutch-American Bicentennial, he was named Knight Officer in the Order of Orange-Nassau by the Dutch government. In 2006, he was named Commander in The Order of Leopold I by the Belgian government.