Circular bronze medal with laterally-pierced loop for ribbon suspension; the face with the head in relief of an unknown man, facing left, wearing spectacles and a traditional soft south German hat decorated with a feather, circumscribed ‘OMNIA AD METAM’ (All - i.e. everyone - to the mark - or winning post) and ‘RITT. WEISSES KREUZ VINDOBONÆ’ (Knights of the White Cross of Vienna) and dated ‘1900-1929’, signed with initials, including the letter ‘M’; the reverse plain; on original trifold ribbon.
Vindobona was the Roman name for Vienna, so we can place and date the medal quite precisely. The White Cross was founded in Berlin in 1890 and was an evangelical Christian organisation.
The portrait may be that of the head of the White Cross in Vienna and commemorate his tenure from 1900 to 1929. but this is conjecture rather than certainty.
An interesting medal.