Heilbrunn Timeline of Art History
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Part of the Metropolitan Museum of Art's website. Browse art by culture, region, thematic category and era. Includes background information and key events for each timeline. There are also thematic essays on a broad number of topics. The information here is written for adults, or perhaps high school students, but could be used a resource for gathering information for younger kids. A rich and extensive resource-- to give a better idea of the extent of the site, there are 92 links within the site related to Ancient Greece and 123 related to European Art in Renaissance.
This could be a WONDERFUL source of material to enrich a history course, or a course on another culture.