Born 23 June 1886 in Glatz (modern Kłodzko, Poland, then in German Silesia), in a family of long Silesian ancestry.

In 1904 he joined the Prussian Army and initially served with the Magdeburg-based 2nd 'Prinz Louis von Preussen' Infantry Regiment.

The following month he became the commanding officer of the 44th Infantry Division, with which he took part in the initial stages of World War II.

After the end of hostilities in October 1939 he was temporarily withdrawn to the personal reserve of the OKH, but was soon reinstated to active service as a provisional commanding officer of the XXIII Army Corps, with which he took part in the battle of France of 1940.

[1] Shortly before the start of Operation Barbarossa, Schubert was promoted to the rank of General of the Infantry and his corps was relocated to East Prussia.