 The two ships performed the normal routine of peacetime cruises and goodwill visits throughout the 1920s and early 1930s; both were placed in reserve in 1933.Both "Andrea Doria" and "Caio Duilio" went into drydock in the late 1930s for extensive modernizations; this work lasted until October and April 1940, respectively.By that time, Italy had entered World War II on the side of the Axis powers.