Starting in November 1918, "Andrea Doria" was based in Taranto. On 10 November, she was sent to Corfu, where she remained until 19 February 1919. She then returned to Taranto, before proceeding to Constantinople in July, departing on the 4th and arriving on the 9th of the month. She joined an Allied fleet in the city and remained there until 9 November, when she returned again to Taranto. In 1920, most of the Italian fleet was temporarily demobilized to provide crews to bring ex-German warships that had been awarded to Italy under the Treaty of Versailles; "Andrea Doria" was the only battleship to remain operational during the period. In November, the Treaty of Rapallo was signed with the Kingdom of Serbs, Croats and Slovenes. "Andrea Doria" was sent to remove the rebellious forces of Gabriele d'Annunzio from Fiume that month. On 24 December, she joined the attack on Fiume, and two days later fired three salvos from her 76 mm guns at the destroyer , which had rebelled and joined d'Annunzio. "Andrea Doria"s gunfire badly damaged "Espero". "Andrea Doria" also shelled d'Annunzio's headquarters and wounded him; he surrendered on 31 December.