Born in Great Britain, Ellenshaw lived in California for many years. His works were represented in public and private collections throughout the world. Peter Ellenshaw described his paintings as his own individual kind of realism. His paintings represented the truth of a scene as he saw it: "A picture must look real. If I can't believe the picture I paint, I am not satisfied. Paintings must be alive." Ellenshaw's canvases were infused with his passion for the land and the sea. He was able to evoke an immediate response in lovers of nature as he colored his canvases with a combination of technical skill and poetic imagination.