I would like to thank the following people for their invaluable help with this book: Rosie de Courcy, Mari Roberts, Simon Bainbridge, Victoria Leacock, Kelley Ragland, Mark Poltimore (chairman, nineteenth- and twentieth-century paintings, Sotheby’s), Louis van Tilborgh (curator of paintings, Van Gogh Museum), Gregory DeBoer, Rachel Rauchwerger (director, Art Logistics), the National Art Collections Fund, Courtauld Institute of Art, John Power, Jun Nagai, and Terry Lenzer.