Ernst Rahn Military Status

I received this photo which pictures my Great-Great Grandfather, Ernst August Friedrich Rahn,  in his military uniform.from my Great-Uncle Ronnie awhile ago. It only just now occurred to me to use this photo to glean some information about where and when Ernst served. After hours of pouring over hundreds of Prussian military photos and starting to think that the photo I had was a fake, I came across germancolonialuniforms.co.uk—a website that provides detailed explanations of German military uniforms and their distinguishing features.

I sent the photo to the website creator Chris Dale who was able to tell me the following:

I would say your great grandfather was an NCO in a Dragoon Cavalry Regiment. The white cuff decorative lace and white helmet plume shows us it is one of two regiments-

• 2. Garde-Dragoner-Regt. Kaiserin Alexandra von Rußland (Berlin) Garde-Korps

• Dragoner-Regt. Königin Olga (1. Württembergisches) Nr.25 (Ludwigsburg) XIII Armee Korps

You say he was Prussian? Then it’s probably the first of those options based in Berlin.

He also suggested that I post the photo to the Pickelhaubes forum. So as I wait for my account on the forum to be activated I’ve been trying to use what information I’d gotten to find some military records on Ancestry.

TRANSLATION: Rahn, Ernst Friedrich,  Field = Secretary Post  u. Head  d. Fieldpost = Expedition

1. Cavalry = Division

The above I found under Germany & Austria, Military and Marine Unit Histories, 1760-1930 in my Ancestry military records search, but the record was published 1870—about the same year Ernst was born.I was thinking that maybe it could be his father or something.

I also found which was under Rank and District of the Royal Prussian Army, 1890; it provides information on what I think is the 1. Kaiserin Alexandra Garde-Korps, but I think I could be wrong about that.