ArtLex
Art Lex: Hellenistic Art Period
Artlex.com defines and describes the Hellenistic period in Western art. Features include links to illustrated examples, artists, and related terms.
Other
1st Muse: Hellenistic Art
This site from 1st Muse discusses the start of Hellenistic art, and the places in which it was formed.
ArtLex
Art Lex: Roman Art
Artlex.com surveys Roman art and artists with text and illustrated examples. Features include links to related terms, concepts, art examples, and the like.
University Press
University Press: Ancient Greece: Time Periods
Looks at periods in the history of Greece going back to 6000 BC. Covers Neolithic, Early Bronze, Minoan, Mycenaean, Dark Ages, Archaic, Classical, and Hellenistic. Each period links to a page of more detailed information.