Saint Mark, Saint Luke, Saint Matthew and Saint John the Evangelist. Lithograph by G. Markendorf after G.F. Barbieri, il Guercino.

Licence: Public Domain Mark

Credit: Saint Mark, Saint Luke, Saint Matthew and Saint John the Evangelist. Lithograph by G. Markendorf after G.F. Barbieri, il Guercino. Wellcome Collection. Source: Wellcome Collection.