About

From overview

Starting on Thursday Dec 4, 2008, Wikimedia Commons witnessed a massive upload of new images. We received nearly 100,000 files from a donation from the German Federal Archives. These images are mostly related to the history of Germany (including the German Democratic Republic) and are part of a cooperation between Wikimedia Germany and the Federal Archives.

Re-use

Site says:

These images are licensed Creative Commons Attribution ShareAlike 3.0 Germany License (CC-BY-SA). Wikimedia Germany and the Federal Archives have signed a cooperation agreement that, among other things, asserts that the Federal Archives owns sufficient rights to be able to grant this kind of license.