One of the most controversial episodes in Blake's career involved a commission from the engraver and printer Robert Cromek (who earlier had turned over Blake's engravings for The Grave to another engraver) to produce a sizeable engraving of Geoffrey Chaucer's pilgrims on the way to Canterbury. Although Blake apparently had a verbal agreement with Cromek to produce this large engraving, Cromek subsequently commissioned the same work from the painter Thomas Stothard, a friend of Blake. An irate Blake accused Stothard and Cromek of stealing his ideas for the print and his commission and ended his friendship with both men. Blake later produced a 54"x 18" tempera painting of the Canterbury pilgrims which he exhibited at his art show in 1809.

In two prospectuses for the Canterbury picture and in his Descriptive Catalogue for his 1809 exhibit, Blake commented extensively on this work. Of his subject for his "Cabinet Picture in Fresco," as the catalogue called the work, Blake stated, "Of Chaucer's characters, as described in his Canterbury Tales, some of the names or titles are altered by time, but the characters themselves for ever remained unaltered, and consequently they are the physiognomies or lineaments of universal human life, beyond which Nature never steps."

In his description of this picture in the Catalogue, Chaucer delineates the character of each pilgrim as he saw it. Charles Lamb considered Chaucer's analyses of the individual pilgrims to be the finest criticism he had ever read of the Canterbury Tales. In a letter to a friend in 1824, Lamb said of Blake and this painting,

Blake is a real name, I assure you, and a most extraordinary man if he be still living. . . . His pictures--one in particular, the Canterbury Pilgrims (far above Stothard's)--have great merit, but hard, dry, yet with grace. He has written a Catalogue of them, with a most spirited criticism on Chaucer but mystical and full of Vision. . . . I must look upon him as one of the most extraordinary persons of the age.

Blake's Descriptive Catalogue provided many of his most important and extensive statements on art and artistic values.