Russia and former USSR
Military commissariat (Russian: Военный комиссариат), abbreviated as voyenkomat (voenkomat) is а local military administrative agency in the former Soviet Union as well as in present-day Russia and some other CIS countries that prepares and executes plans for military mobilization, maintains records on military manpower and economic resources available to the armed forces, provides premilitary training, drafts men for military service, organizes reserves for training, and performs other military functions at the local level.
Voennyi komissariat is headed by an officer called voenkom (Russian: военком) in Russian, which is an abbreviation for voennyi komissar (Russian: военный комиссар), translated simply as "military commissar".
Elsewhere in Europe
The word commissariat, within the Military of France and the Military of Italy (and formerly in the British Army) designates services providing supplies, as well as financial and legal support to units, roughly equivalent to the Quartermasters in the US military. Officers from these services are called commissaires (in French), commissari (in Italian) and commissaries in English.