When Henry Lincoln first began researching the story of a French village priest who was led by secret parchments to the source of great wealth, he explored tempting possibilities. Had the priest found the lost treasure of Jerusalem concealed by the Visigoths, or that hidden by the Templars, or was it even the Holy Grail?

In this Chronicle programme Henry Lincoln explains how the mystery led him from the documents of a French secret society to an English stately-home before he discovered part of the solution hidden in Poussin's celebrated painting 'Les Bergers d'Arcadie'.