Today, for your lesser-known saint day shout-out, we have Bartolome de Las Casas (1566), who generally made all of his colleagues upset when he was made Bishop of Chiapas and prohibited slavery and argued for the humane treatment of native Guatemalans.

“The (Guatemalans) are our brothers, and Christ has given his life for them. Why, then, do we persecute them with such inhuman savagery when they do not deserve such treatment?” from New Book of Festivals & Commemorations by Pfatteicher