Pierre de Valenciennes: Pioneer of Open-Air Painting and Romantic Landscape Pierre Henri de Valenciennes (1750 – 1819) stands as a pivotal figure in the burgeoning landscape movement of the late Enlightenment and early Romantic eras. Often overshadowed by his contemporaries, Valenciennes’s contribution to artistic innovation—specifically his championing of “landscape portraits”—laid the groundwork for a new approach to painting that p…