After severe losses during the Battle of the Lys in April 1918 the corps was moved south to a quiet sector to reform. This sector was the unlucky target of the next German offensive, the Third Battle of the Aisne in May–June 1918, causing further losses to IX Corps. General Duchêne, commander of the French Sixth Army, had deployed IX corps (five divisions) too far forward, on the Chemin des Dames ridge which had been gained at such cost in the Second Battle of the Aisne the previous year. (The French Commander-in-Chief Petain and the Army Group Commander Franchet d’Esperey would have preferred the ridge to be lightly held and the main defence to be a battle zone between it and the River Aisne).