The Upper Basilica of St. Francis in Assisi.
“St. Francis’ affinity for the environment influenced the artist Giotto (ca. 1270–1337), who revolutionized art history by painting figures which were three dimensional and including natural elements in his religious works. By taking sacred images away from Heaven and placing them in an earthly landscape, he separated them definitively from their abstract, unapproachable representation in Byzantine art.
“Giotto’s works are distinctive because they portray daily life as blessed, thus demonstrating that the difference between the sacred and profane is minimal. Disseminating the new ideas of St. Francis visually was very effective, as the general populace was illiterate. Seeing frescoes reflecting their everyday lives in landscapes that were familiar changed their way of thinking. The trees, plants, animals and rocky landscapes were suddenly perceived as gifts from the Creator to be used, enjoyed and respected. Furthermore, Giotto recognized that the variety of dramatic landscapes would provide spectacular visual interest in the works.”
From St. Francis and Giotto: The Saint and the Artist Started the Ecological Movement