[2] His earliest documented altarpiece is a Coronation of the Virgin (1515–1516) commissioned by Dr. Peter von Clapis, a professor at the University of Cologne.
He was the first important portrait painter in Cologne, and the founder of a prolific school of portraiture that was continued by his sons Arnt and Barthel Bruyn the Younger.
[1] His subjects are usually portrayed at half-length against a flat background; the face is the center of attention, but costume details are crisply described, and prominence is given to the hands.
Art historian Jean M. Caswell says Bruyn's depictions of the upper-middle-class citizens of Cologne are "lively and expressive, and they show no vain flattery".
[2] His works are in numerous public collections, including the National Gallery, London; the Metropolitan Museum of Art in New York; and the Louvre in Paris.