In April 1885, Vincent wrote his brother Theo about his first masterpiece, The Potato Eaters. He was currently working on the painting, which was to become one of his first complex compositions with multiple figures, and illustrated the letter with a sketch of the work, writing "See, this is what the composition has now become. I’ve painted it on a fairly large canvas, and as the sketch is now, I believe there’s life in it."

Theo "was the kind of man who saved even the smallest scrap of paper", and it is to this trait that we owe the 663 letters from Vincent. The letters play a big role in shedding light on his art and emotions. He included in the letters sketches of common people such as miners and farmers for he believed the poor would inherit the earth. Van Gogh's spiritual and theological thought and convictions are revealed in his letters throughout his life.