De Es was born in 1942 in Gresten, Lower Austria, as Dieter Schwertberger. He studied the painting technique of the Old Masters in Vienna and is an independent artist since 1962. He lived three years in Switzerland and twelve years in New York City. He lives again in Vienna since 1986.
The artist considers himself to be a seeker, who shows what he has found through "the language of the images". His message of "meaning and transformation" finds clear and intense expression in his paintings through a precise use of space, light and texture.