When the Franco-Prussian War broke out in July 1870, Bataille was in command of the 2nd Division of "général de division" Charles Auguste Frossard's II Army Corps. His division led Frossard's forces in the war's opening battle, the Battle of Saarbrücken, on 2 August 1870. At the Battle of Spicheren on 6 August, Frossard placed Bataille's division in reserve, but Bataille committed the division to action without orders from Frossard, splitting it into two parts to support the French line against the German attack and shoring up the French line, although denying Frossard any opportunity to maneuver by committing his reserve. Judging the threat on the French left to be growing, Bataille on his own initiative detached a regiment to reinforce the left, and at the end of the day had to extract the elements of his division on the French right around Stiring-Wendel under difficult circumstances as the French army pulled back from the battlefield.