Hans Holbein the Younger
The Solothurn Madonna
Museum of the City of Solothurn, Switzerland
The museum identifies the figure on the left as St. Martin of Tours; he has no attributes other than his episcopal garb and crozier. On the right is the St. Ursus the soldier who escaped the massacre of the Theban Legion but was later found in Solothurn and martyred there. His armor is of course the kind worn by contemporaries of the artist.
Read more about St. Ursus, St. Martin of Tours and the Madonna and Child.
Source: Wikimedia Commons