All four ships were deployed to the Mediterranean Sea for the entirety of World War I, spending most of their time escorting French troop convoys from North Africa and covering the Otranto Barrage.

An Anglo-French fleet led by Courbet succeeded in sinking the Austro-Hungarian protected cruiser Zenta in the Battle of Antivari.

Between the wars the surviving ships were modernised several times, but they were not rebuilt thoroughly enough to prevent them from becoming obsolete in comparison to modern German or Italian battleships.

[8] The Courbet-class ships were completed less than a year before the start of World War I and nothing is known of their activities during this time except that France, escorted by Jean Bart, carried the President of the French Republic, Raymond Poincaré, on a state visit to Saint Petersburg, Russia in July 1914.

Courbet became the flagship of Admiral Augustin Boué de Lapeyrère, commander of the French Mediterranean Fleet.

Lapeyrère decided immediately on a sweep into the Adriatic to surprise the Austrian vessels enforcing a blockade of Montenegro.

The Anglo-French force, which included Jean Bart, succeeded in cutting off and sinking the Austro-Hungarian protected cruiser Zenta off Bar on 16 August 1914, although her accompanying destroyer managed to escape.

[10] They spent most of the rest of 1914 providing gunfire support for the Montenegrin Army until U-12 hit Jean Bart on 21 December with one torpedo in the wine store just in front of the forward magazine off Sazan Island.

[11] A post-war assessment listed their weaknesses as: The survivors were refitted several times during the interwar period to remedy these issues, although no comprehensive modernisation was ever planned.

[12] In April 1919, while helping to defend Sevastopol from the advancing Bolsheviks, the crews of France and Jean Bart mutinied, but collapsed when Vice-Admiral Jean-Françoise-Charles Amet agreed to meet their main demand to take the ships home.

26 crewmen on France and three on Jean Bart were sentenced to prison terms upon her return, although they were commuted in 1922 as part of a bargain between Prime Minister Raymond Poincaré and the parties of the Left.

[13] In 1922, France was wrecked after striking an uncharted rock in Quiberon Bay at low tide and foundered with three deaths among her crew.

The following year she became a gunnery training ship at Toulon, but she suffered a serious boiler fire in June 1923 that caused her to be repaired and given the first of her upgrades between July and April 1924 at La Seyne-sur-Mer.

She had another boiler fire in August 1924 and remained under repair for the rest of the year, but resumed her duties as a gunnery training ship upon her return from the dockyard.

By 1939 she reverted to her role as a gunnery training ship, but she was ordered to Brest and Quiberon with her sister Paris upon the outbreak of World War II.

She supported an amphibious landing at Al Hoceima by Spanish troops during the summer of 1925 after the Rifians attacked French Morocco during the Rif War.

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

Both ships were ordered restored to operational status on 21 May 1940 by Amiral Mord and their light anti-aircraft outfits were augmented at Cherbourg.

She was also seized there on 3 July and was turned over to the Free French a week later who used her as a depot and an anti-aircraft ship in Portsmouth until 31 March 1941 when she was disarmed.

She was used for experiments with large shaped charge warheads by the Germans until she was sunk by the Allies in 1944[3] before being broken up in place beginning on 14 December 1945.