One of the great mysteries of 17th century Dutch art is the identity of the artist known as Master I.S. The works of this enigmatic painter, though limited in number, hold a prominent place in major art collections around the world. Counted among the artists of the School of Rembrandt, Master I.S. is best known for studies of elderly people and scholars in their studios. The known oeuvre is closely associated with Leiden artists such as Rembrandt, Jan Lievens and Gerrit Dou but also contains references to Scandinavia and Eastern Europe. 

The exhibition and research project Master I.S. – Enigmatic Contemporary of Rembrandt is a collaboration between Serlachius in Mänttä, Finland and Museum De Lakenhal in Leiden, the Netherlands.

This book represents the first comprehensive study of the artist's career. It is edited by the curators of the exhibition, Tomi Moisio and Janneke van Asperen. In addition to contributions by the curators, this book contains an elucidatory essay by renowned experts of Dutch art, Professors Volker Manuth and Marieke de Winkel, who have been studying the oeuvre of this mysterious artist for years.