Michel was born in the village of Auteuil (now part of the 16th arrondissement of Paris), the son of a policeman. He attended the École spéciale militaire de Saint-Cyr from 1867 to 1869. On 1 January 1870, he entered the École d'état-major (Staff College), but the Franco-Prussian War made him leave school in October 1870 to join the 13th Army Corps and he served at the Siege of Paris as a lieutenant. In November 1870, he was assigned to the 3rd Division of the 2nd Army of Paris as a lieutenant. During the Battle of Villiers on 30 November 1870, he was wounded in the face.