Courtesy of dpreview:
Europeana Photography is a new online image archive that includes more than 2 million historical photographs from European collections in 34 countries, covering the first 100 years of photography. The 2,296,517 photos in the gallery were sourced from photographic archives, agencies and museum collections across Europe and can be filtered by the providing country, institution, and usage license. Many of the images are Public Domain.
Click here to view archive.