Germany issued this set of overprints on 1 October 1900. The underlying stamps are German Germania issues from 1900 (MiNr. 54 a - 62 and MiNr. 63 a - 66 IV).
The stamps can be distinguished from later overprints by their use of Antiqua font on 'REICHSPOST' stamps.
In 1903, a second printing of these stamps (Michel suffix '"II") was released, with the 1903 issues having a slightly different overprint.