She survived the war, and continued to serve in the post-war Italian navy, primarily as a training ship.

Steam was provided by eight oil-fired and twelve coal- and oil-burning Yarrow boilers that were ducted into two large and widely spaced funnels.

[1] She saw no action in World War I, given the fact that the Austro-Hungarian fleet, Italy's main naval rival, remained in port for the duration of the conflict.

[3] In addition, Admiral Paolo Thaon di Revel, the Italian naval chief of staff, believed that Austro-Hungarian submarines and minelayers could operate too effectively in the narrow waters of the Adriatic.

[4] Instead, Revel decided to implement blockade at the relatively safer southern end of the Adriatic with the battle fleet, while smaller vessels, such as the MAS boats, conducted raids on Austro-Hungarian ships and installations.

Meanwhile, Revel's battleships would be preserved to confront the Austro-Hungarian battle fleet in the event that it sought a decisive engagement.

She returned to Smyrna after completing her deployment to the Black Sea, and remained there until 9 September, when she was relieved by the battleship Giulio Cesare.

Placed back into service in 1920, Duilio went to Albania on 30 June to support the Italian Army contingent occupying the country, and participated in their withdrawal on 5 September.

[7] On the night of 10–11 November, the British Mediterranean Fleet launched a surprise air raid on the harbor in Taranto.

Twenty-one Swordfish torpedo bombers launched from the aircraft carrier HMS Illustrious attacked the Italian fleet in two waves.

[8] The torpedo hit Duilio on her starboard side; it tore an 11-by-7-meter (36 by 23 ft) hole in the hull and flooded the forward main battery magazines.

[7] While Duilio was in dock for repairs, the British Force H departed from its normal role as a convoy escort in the western Mediterranean in early February to attack Genoa.

Admiral James Somerville's surface ships fired over a thousand shells at the port, and aircraft of the carrier HMS Ark Royal dropped magnetic mines in the harbor.

During the convoy operation, British forces attacked, resulting in the First Battle of Sirte, but Duilio's group was too far away to engage the Royal Navy.

[7] Duilio's next operation was a sortie against the British convoy MW 9 bounded from Alexandria to Malta in February.

She departed from Taranto on 14 February with a pair of light cruisers and seven destroyers, but the force could not locate the British ships, and so returned to port.

Her mere presence at sea, however, forced the British escort to scuttle the transport Rowallan Castle, previously disabled by German aircraft.

By this point in 1942, the Italian fleet began to suffer a severe shortage of fuel, which curtailed its operations.

The situation was so bad that Duilio had to be placed in reserve and drained of fuel, in order to keep the escort craft operational.

[7] In June 1944, the Allies allowed Duilio to return to Italian ports; she spent the rest of the war in Taranto, Syracuse, and Augusta.

She survived the war, and continued to serve in the Italian navy; she was the fleet flagship from 1 May 1947 until 10 November 1949, based in Taranto.