The Bretagne-class battleships were the first "super-dreadnoughts" built for the French Navy during the First World War. The class comprised three vessels: Bretagne, the lead ship, Provence, and Lorraine. They were an improvement of the previous Courbet class, and mounted ten 340 mm (13.4 in) guns instead of twelve 305 mm (12 in) guns as on the Courbets. A fourth was ordered by the Greek Navy, though work was suspended due to the outbreak of the war. The three completed ships were named after French provinces.

The three ships saw limited service during World War I, and were primarily occupied with containing the Austro-Hungarian Navy in the Adriatic Sea. After the war, they conducted training cruises in the Mediterranean and participated in non-intervention patrols off Spain during the Spanish Civil War. After the outbreak of World War II, the ships were tasked with convoy duties and anti-commerce raider patrols until the fall of France in June 1940. Bretagne and Provence were sunk by the British Royal Navy during the Attack on Mers-el-Kébir the following month; Provence was later raised and towed to Toulon, where she was again scuttled in November 1942. Lorraine was disarmed by the British in Alexandria and recommissioned in 1942 to serve with the Free French Naval Forces. She provided gunfire support during Operation Dragoon, the invasion of southern France, and shelled German fortresses in northern France. She survived as a gunnery training ship and a floating barracks until the early 1950s, before being broken up for scrap in 1954. Bretagne and Provence were scrapped in 1952 and 1949, respectively.

By 1910, France had yet to lay down a single dreadnought battleship; Britain had by then completed ten dreadnoughts and five battlecruisers, with eight and three more of the two types, respectively, under construction. Germany had built eight dreadnoughts and one battlecruiser and the United States had six built and four more building. Late that year, the French Navy laid down the first of the four Courbet class ships. To remedy the inferiority of the French fleet, the government passed the Statut Naval on 30 March 1912, authorizing a force of twenty-eight battleships, to be in service by 1920. The first three ships were to be laid down in 1912.^[1]

The Bretagne class were replacements for the battleships Carnot, Charles Martel and Liberté. They were developed from the Courbet class, and were built with the same hulls.^[2] The primary reason for the decision to use the same hull design as the Courbet class was limitations of French shipyards. The Courbet-class ships were the largest possible ships that could fit in existing dockyards and refitting basins. The Superior Naval Council (Conseil supérieur de la Marine) ordered the construction department to prepare designs for a 23,500-metric-ton (23,100-long-ton; 25,900-short-ton) ship armed with twelve 340 mm (13.4 in) guns in six twin gun turrets.^[3]

The additional weight of the 340 mm turrets compared to the 305 mm (12 in) of the Courbet-class ships imposed insurmountable problems for the designers. To incorporate six turrets with the same arrangement of the earlier vessels, with four on the centerline in superfiring pairs and two wing turrets amidships would have required an additional 3,000 metric tons (3,000 long tons) displacement as well as a significant increase in the length of the hull. After several other proposals, the Superior Naval Council chose a design with five twin turrets, all mounted on the centerline.^[3] This would achieve the same broadside of ten guns, despite the reduction in the number of guns.^[4] The width of the armored belt was reduced by 20 mm (0.79 in) to compensate for the increased weight of the main battery.^[3]

Provence was the first ship of the class to be laid down, which she was on 21 May 1912 at the Arsenal de Lorient. Bretagne was laid down at the Arsenal de Brest shipyard in Brest on 22 July 1912. Lorraine followed at the Ateliers et Chantiers de la Loire shipyard in St. Nazaire almost six months later on 7 November 1912.^[5] Due to the outbreak of World War I in the summer of 1914, French industrial capacity was redirected to the army and work slowed on the ships.^[6] The Greek Navy ordered a battleship to be named Vasilefs Konstantinos to the same design from AC de St Nazaire Penhoet. Work began in June 1914 but ceased on the outbreak of war in August and never resumed. The contract dispute was settled in 1925.^[7]

All three ships of the class entered service with the French Navy in 1916. Bretagne and Lorraine were assigned to the 1st Division of the 1st Battle Squadron, while Provence served as the fleet flagship for the entirety of the First World War. They were deployed to guard the southern end of the Adriatic Sea, based in Argostoli and Corfu, to block a possible sortie by the Austro-Hungarian fleet. The three ships largely remained in port, though Provence was repeatedly used to intimidate the government of Greece, which favored Germany during the war.^[11] In January 1919, after the end of the war, Lorraine was sent to Cattaro to guard the Austro-Hungarian fleet. She joined her sisters in Toulon in June 1919; later that year the ships formed the Eastern Mediterranean Fleet until 1921.^[20]

Financial problems forced the French Navy to reduce its battleship force to four active vessels. Lorraine and Provence were reduced to reserve status in 1922, and the latter went into drydock for a major overhaul.^[20] Lorraine returned to service with the Mediterranean Squadron in 1923.^[21] Bretagne remained in service and conducted training cruises in the Mediterranean and along the coast of North Africa during the 1920s and 1930s. In 1934, Bretagne and Provence were assigned to the 2nd Squadron, based on France's Atlantic coast. In 1936, they joined the non-intervention patrols off Spain during the Spanish Civil War.^[20] At the outbreak of World War II in September 1939, Bretagne and Provence were based in Toulon with the 2nd Squadron, while Lorraine was assigned to the Atlantic Squadron.^[22]

After undergoing a refit in the early months of the war, Provence conducted anti-raider patrols with Force Y, based in Casablanca. Bretagne was also overhauled early in the war; in March 1940 she escorted a convoy to Halifax and returned with another convoy loaded with aircraft for the French Air Force. She was then ordered to join Lorraine in Force X, to be based in Alexandria to operate in concert with the British Mediterranean Fleet. Two weeks later, Bretagne was instead ordered to steam at high speed to Bizerte, to join the Force de Raid with Provence. The ships put in at Mers-el-Kébir and remained there until after the fall of France in June 1940.^[21] To prevent the ships of the French Navy from falling into the hands of the occupying Germans, British Prime Minister Winston Churchill ordered the neutralization of all French warships. Force H was to deliver an ultimatum to the ships based at Mers-el-Kébir; on 3 July, the British squadron arrived outside the harbor and demanded that the ships sail with them to Britain or they would be sunk.^[23]

The British and French negotiated for several hours, and culminated in the British opening fire on the French fleet. In the span of ten minutes, Bretagne was sunk and Provence was badly damaged.^[24] Bretagne was hit by at least four 15 in (380 mm) shells from HMS Hood, Resolution and Valiant and exploded, killing the vast majority of her crew. Provence was set on fire and sank to the bottom of the harbor,^[21] though she was subsequently raised and transferred to Toulon, where she was later scuttled in 1942 to prevent her from being seized by the Germans. They nevertheless salvaged the ship starting in July 1943.^[25] Two of her main guns were emplaced as coastal batteries outside Toulon. Lorraine was disarmed in Alexandria until December 1942, when she joined the Free French Naval Forces. She served as a training ship for much of 1943 until a major refit at the end of the year to prepare her to participate in Operation Dragoon, the invasion of southern France. She provided gunfire support during the landings before steaming to Britain for a minor refit. She remained in Britain until March 1945, when she bombarded German-held fortresses in northern France.^[21]

After the end of the war, Lorraine served as a gunnery training ship in Toulon. She was then used as a barracks ship until February 1953, when she was stricken from the naval register and sold for scrapping at the end of the year. She was broken up for scrap outside Toulon the following year. Bretagne remained at the bottom of Mers-el-Kébir until she was raised for scrapping in 1952 and broken up. Provence was raised in April 1949 and scrapped.^[21]