General Military Chancellery
The General Military Chancellery (Ukrainian: Генеральна військова канцелярія, romanized: Heneraljna vijsjkova kanceljarija) was the highest administrative institution of the Cossack Hetmanate in the 17th and 18th centuries. It was the central governing body responsible for communications, document flow, administrative work, and document storage.
Source: Wikipedia — General Military Chancellery (CC BY-SA 4.0)