Gertrude Vernon, or Lady Agnew of Lochnaw, was an English woman who married a Scot. The American artist John Singer Sargent excelled as a painter in Europe. His portrait of Lady Agnew was painted in London but has found its definitive home in Edinburgh. All these contexts converge in a supremely beautiful painting which is one the icons of the collection of the National Galleries of Scotland.

Created in the 1890s, it proved to be a seminal work in the lives of the artist and his subject and has enjoyed a rich afterlife, inspiring artistic and written responses. This book offers a fascinating biography of this most accomplished, evocative and admired of portraits, placing it in the context of Sargents career and how he worked, discussing the life of the sitter and unveiling the pictures rich critical history.