Hi,
I only came across this topic today, but can give some brief bios of a number of the German Landeswehr officers pictured:
Kom. Barth:
Heinrich Eduard Johann Barth (31 Aug 1890 - 23 Oct 1942)
Lt. Colonel in the Latvian Army (13th Tukums Inf. Reg.)
Jan 1920 - ?: Intendant, German Landeswehr
? - Aug 1921: Intendant, 13th Tukums Infantry Regiment
? - ?: repeatedly acting Commanding Officer, 13th Tukums Infantry Regiment
Aug 1921 - 11 Nov 1921: Supernumary officer, 13th Tukums Infantry Regiment
11 Nov 1921: Retired
Kom. von Hahn:
Karl Richard Alexander von Hahn (16 Sep 1889 - 10 Aug 1942)
Lt. Colonel in the Latvian Army (13th Tukums Inf. Reg.)
Jul 1919 - Apr 1920: Officer, German Landeswehr
Apr 1920 - Apr 1921: Squadron Commander, 13th Tukums Infantry Regiment
Apr 1921 - 1 May 1921: Supernumary officer, 13th Tukums Infantry Regiment
1 May 1921: Retired
Rittm. von Hahn:
Joachim von Hahn
Captain in the Latvian Army (13th Tukums Inf. Reg.)
Commanding Officer, II Battalion, 13th Tukums Infantry Regiment
Maj. von Rhaden:
Wolfert Gerhard von Rhaden (28 May 1893 - 1 Oct 1943)
Lt. Colonel in the Latvian Army (13th Tukums Inf. Reg.)
24 Jul 1919 - Apr 1920: Staff Officer, German Landeswehr
Aug 1919: promoted to Lt. Colonel
Apr 1920 - Aug 1920: Battalion Commander, 13th Tukums Infantry Regiment
Aug 1920 - ?: Acting Commanding Officer, 13th Tukums Infantry Regiment
? - Mar 1921: Battalion Commander, 13th Tukums Infantry Regiment
Mar 1921: Retired
Very best regards,
VJK