 The window dates to 1868 and was donated to the cathedral by Monseigneut Renė Nicolas Sergent and was the work of Hirsch, Erdmann and Kremer.In the tracery are the arms of Monseigneur Rėne Nicolas Sergent.Above the altar are murals painted by Yann Dargent which show John preaching on the banks of the Jordan river and his baptising Jesus.