It was based within Germany proper and included command and administrative units as well as training and guard troops.
Its primary role was to provide replacements for the combat divisions of the regular army.
[2] The Ersatzheer contingency plans for Operation Valkyrie were deliberately misused as part of the unsuccessful 20 July plot to assassinate Adolf Hitler, arrest SS troops, and stage a military coup d'etat through the organization driven by the newly appointed Chief of Staff, Claus von Stauffenberg, in early 1944.
[3] Fromm had refused to cooperate in an earlier coup, Operation Spark, but the planners in 1944 still planned to use the Replacement Army.
Heinrich Himmler personally took over control of the Replacement Army because of its potential to be used in another assassination attempt.