This tempera on wood, created by the Catalan painter Lluis Borrassa (born in Gerona, ca. 1360, died in Barcelona, 1425) depicts Peter, a disciple of Jesus, as he walks on water.
The work (St. Peter is Walking on the Water), which Borrassa created between 1411-13, is at Sant Pere (St. Peter's) in Terrassa, Spain.
Image online, courtesy Wikimedia Commons.