After the Young Turk Revolution and the establishment of the Second Constitutional Era on July 3, 1908, the new government initiated a major military reform. Army headquarters were modernized. Its operational area was Constantinople and the Bosporus, and it had units in Europe and Asia Minor. It commanded the following active divisions:Edward J. Erickson, Defeat in Detail: The Ottoman Army in the Balkans, 1912-1913, Westport, CT: Praeger, 2003, p. 17. The First Army also had inspectorate functions for four Redif (reserve) divisions:Edward J. Erickson, Defeat in Detail: The Ottoman Army in the Balkans, 1912-1913, Westport, Praeger, 2003, p. 19.T.C. Genelkurmay Başkanlığı, Balkan Harbi, 1912-1913: Harbin Sebepleri, Askerî Hazırlıklar ve Osmanlı Devletinin Harbe Girişi, Genelkurmay Basımevi, 1970, pp. 87-90.
