Casement wrote to him at "III, 48 Wilhelmstrasse ". I am not clear whether he was "political" or "regular".
1915 Oct 26. Monteith writes - Travel to Zossen with Sir Roger and Major von Baerle of the War Office. The men were paraded (number on parade 50) S.R.C. spoke to them informing them that in future I was to be regarded as their commanding officer (or until such time as a senior officer arrived from America). I also said a few words to them. Lunched at the German officers mess. Returned to Berlin same evening.
1915 Nov 13. Monteith writes - Have up to now selected 52 men who will in all probability join us. The War Office will not give me permission to wear uniform, which would assist me greatly in the work. Major von Baerle from. the War Office came to Limburg to see how things were going. He wanted to remain in the room whilst I was speaking to the men, but I objected as it had been said before that the men would not be interviewed before a staff of German Officers.
1915 Nov 24. Monteith writes Reach Berlin Zerhusen and I go to War Office and see Major von Baerle, who has charge of our affairs. He is unable to give me permission to go to Zossen or to wear uniform, and requests me to stay in Berlin for a few days until the General Officer Commanding gives the necessary authority. 27 Nov 1915 was when permission was finally given for Monteith to wear the Irish uniform.
1915 Dec 2. Casement writes to von Baerle that McGoey was willing to join Irish Brigade
1918 Apr .Lt Col von Baerle becomes head of Propaganda Dept in German Foreign Office. von Baerle was replaced by Capt Pflug for whatever his exact role was with Irish Brigade. I have not found any references to von Pflug
Casements Irish Brigade