Before 1809, Eugène never led so much as a regiment into battle, yet Napoleon entrusted him with command of the Army of Italy. To prepare his stepson Eugène for the role, the emperor advised him how to defend Italy in many detailed letters. He wrote that if the Austrians invaded in superior numbers, the viceroy was to give up the Isonzo River line and fall back to the Piave River. The emperor noted that the Adige river was a particularly important strategic position. Napoleon did not believe Austria would attack in April, and in any case, did not wish to provoke his enemy by concentrating his armies. Therefore, Eugène's army remained somewhat dispersed.