High Quality Content by WIKIPEDIA articles! Theodorus "Theo" van Gogh (1 May 1857 - 25 January 1891 ) was a Dutch art dealer. He was the younger brother of Vincent van Gogh, and Theo`s unfailing financial and emotional support allowed his brother to devote himself entirely to painting. Theo died at the age of 33, six months after Vincent died at the age of 37.