She spent the war in the Mediterranean, spending most of 1914 providing gunfire support for the Montenegrin Army until her sister ship Jean Bart was torpedoed by the submarine U-12 on 21 December.

[1] She spent the rest of the war providing cover for the Otranto Barrage that blockaded the Austro-Hungarian Navy in the Adriatic Sea.

She supported Allied troops in the defence of Le Havre during June until she was damaged by a German bomb, but she took refuge later that month in England.

By 1909 the French Navy was finally convinced of the superiority of the all-big-gun battleship like HMS Dreadnought over the mixed-calibre designs like the Danton class which had preceded the Courbets.

The following year, the new Minister of the Navy, Augustin Boué de Lapeyrère, selected a design that was comparable to the foreign dreadnoughts then under construction to be built as part of the 1906 Naval Programme.

[3] These boilers were coal-burning with auxiliary oil sprayers and were designed to produce 28,000 metric horsepower (20,594 kW; 27,617 shp).

The Courbet-class ships carried enough coal and fuel oil to give them a range 4,200 nautical miles (7,800 km; 4,800 mi) at a speed of 10 knots (19 km/h; 12 mph).

Their secondary armament was twenty-two Canon de 138 mm (5.4 in) Modèle 1910 guns, which were mounted in casemates in the hull.

She spent most of the rest of 1914 providing gunfire support for the Montenegrin Army until U-12 hit Jean Bart on 21 December with a torpedo.

This included replacing one set of boilers with oil-fired boilers, increasing the maximum elevation of the main armament from 12° to 23°, removal of her bow armour to make her less bow-heavy, the installation of a fire-control director, with a 4.57 metres (15.0 ft) rangefinder, and the exchange of her Mle 1897 AA guns for Mle 1918 guns.

She destroyed coastal defence batteries there despite taking light damage from six hits and remained there until October as the flagship of the French forces.

Three 1.5-metre (4 ft 11 in) rangefinders were provided for her anti-aircraft guns, one on top of the duplex unit on the conning tower, one on 'B' turret and one in the aft superstructure.

Paris was ordered to Le Havre on 6 June to provide gunfire support on the Somme front and covered the evacuation of the town by the Allies, although the lack of spotting aircraft meant that she was not particularly effective in that role.