Giulio Cesare was one of three dreadnought battleships built for the Royal Italian Navy (Regia Marina) in the 1910s. Completed in 1914, she was little used and saw no combat during the First World War. The ship supported operations during the Corfu Incident in 1923 and spent much of the rest of the decade in reserve. She was rebuilt between 1933 and 1937 with more powerful guns, additional armor and considerably more speed than before.
During World War II, both Giulio Cesare and her sister ship, , participated in the Battle of Calabria in July 1940, when the former was lightly damaged. They were both present when British torpedo bombers attacked the fleet at Taranto in November 1940, but Giulio Cesare was not damaged. She escorted several convoys to North Africa and participated in the Battle of Cape Spartivento in late 1940 and the First Battle of Sirte in late 1941. She was designated as a training ship in early 1942, and escaped to Malta after the Italian armistice the following