The collection now belongs to the City, but it was collected by two generations of Walters men.  It does a good job of being as comprehensive as they intended, although they certainly were not able to buy the very best works by the very best artists.  The collection stops with works made in the late 1800's (meaning only a hint of Impressionism). 
an early Gothic head from St-Denis (outside Paris) of an ancient king but toppled during the French Revolution on the belief it was a French king
Manet's "Cafe-Concert"
There is some very interesting Byzantine early Christian silver plus European "Migration" art (Huns, Franks, Burgundians, Goths, Celts, and Lombards).  The collection is presented chronologically, so this leads to Medieval art (religious works and a Knights Hall).  In more recent centuries they liked Italian art and then French 19th-century works.  Don't miss the Asian collection, partly because it is in an attached Greek Revival mansion on Mount Vernon Square. 
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