French cruiser Jules Ferry

When Imperial Germany declared war on France on 3 August 1914, the ship was still assigned to the 2nd DL. The following day the cruisers were part of the escorting force for a troop convoy from Algiers, French Algeria to Metropolitan France. On 13 August Vice Admiral Augustin Boué de Lapeyrère, commander of the Allied forces in the Central Mediterranean, was ordered to begin offensive operations against the Austro-Hungarian fleet in the Adriatic. He decided to break the Austro-Hungarian blockade of the port of Antivari, Montenegro, and to engage any ships operating out of nearby Cattaro. He split his available forces into two groups with the armored cruisers following the Albanian coast and the battleships tracing the Italian coast before cutting across the Adriatic to rendezvous at Antivari on the morning of the 16th. The latter group sank the protected cruiser SMS Zenta that morning in the Battle of Antivari as the armored cruisers were coming up from the south.[9]

At the end of the month, the French began intermittently escorting single cargo ships to Antivari, usually escorted by the armored cruisers and covered by the main battlefleet. The first of these was on 31 September when four armored cruisers escorted the steamer SS Liamone while the battleships bombarded the defenses of Cattaro. The 2nd DL escorted the cargo ship SS Henri Fraissinet as it brought long-range artillery pieces to Antivari on 18–19 September. On the return voyage, they took advantage of the fog to bombard Cattaro before they were forced to withdraw by the heavy return fire. The 2nd DL participated in the next sortie into the Adriatic on 17 October, but it was uneventful. During the following mission, begun at the end of October, the 2nd DL raided the island of Lastovo on 2 November and Jules Ferry was narrowly missed by U-5, an Austro-Hungarian U-boat, on the return voyage the following day. The cruiser covered the armored cruiser Jules Michelet as she towed the submarine Curie to the vicinity of Pelagosa on 16 December as the submarine lacked the range to attack the naval base at Pola (modern Pula). The torpedoing of the dreadnought battleship Jean Bart five days later brought an end to the sorties into the Adriatic by the battlefleet; henceforth the supply ships were escorted by the armored cruisers or smaller ships. The French also responded by moving their patrol line further south to a line north of the Greek island of Corfu.[10]

Italy signed the Treaty of London on 26 April 1915, agreeing to declare war on Austro-Hungary. Boué de Lapeyrère, concerned about a possible pre-emptive attack on the southern Italian ports, temporarily moved all of his armored cruisers, including the three sisters, closer to the Strait of Otranto that day. Léon Gambetta was torpedoed and sunk by U-5 with heavy loss of life on the 27th. After the sinking, Boué de Lapeyrère withdrew his armored cruisers even further south to a patrol line running through the Gerogombos lighthouse on the island of Cephalonia. He also ordered that patrols should be made at a speed of 14 knots (26 km/h; 16 mph), not the leisurely 6 knots (11 km/h; 6.9 mph) used by Léon Gambetta's late captain. After the Italian declaration of war on 23 May, the French ships withdrew further into the Mediterranean and Ionian Seas with the 2nd DL ultimately basing itself at Alexandria, Egypt, Bizerte, French Tunisia, and British Malta; the division was responsible for patrolling the area between Capo Colonna in southern Italy and the easternmost point of the Greek island of Crete.[11]

At the end of 1915, the French and British decided that the Serbian position in Montenegro and Albania was untenable and that the army would have to be evacuated. They decided to occupy the neutral island of Corfu to provide a place for the Serbs to recuperate and to rebuild their army. Jules Ferry ferried some of the occupation force to Corfu on 11 January 1916. In March, the Allies decided to occupy the Greek island of Argostoli to serve as a base for the battlefleet while the armored cruisers were based further north at Corfu. The Royal Serbian Army was deemed fit for combat in May and the French armored cruisers provided distant cover for the transfer to the Salonica Front until it was completed on 15 June. Shortages of coal and trained manpower hampered most training for the rest of the year and became even worse in 1917. On 12 August, the 2nd DL was disbanded with Jules Ferry assigned to transport duties for the next year and her other sister, Victor Hugo, was reduced to reserve.[12]

Jules Ferry joined her sister in reserve in Bizerte in July 1918; they were reactivated in 1921 and assigned to the Atlantic Flying Division (Division volante de l'Atlantique). Two years later Jules Ferry was transferred to the Far Eastern Division (Division navale de l'Extrême Orient). Departing on 27 September 1923, she arrived in Saigon, French Indochina, on 21 November. Her service there was uneventful and the ship arrived back in Toulon on 10 November 1925 at which time she was placed in reserve. Jules Ferry was stricken from the Navy List on 19 January 1927 and sold for scrap the following year.[13]