French destroyer L'Indomptable

In April 1939 the bridge wings were enlarged to accommodate the Hotchkiss machine guns. After the war began, depth-charge stowage increased to 48 and a pair of rails were installed on the stern for 35-kilogram (77 lb) depth charges. Each rail could accommodate 3 depth charges and 15 more were stored in the magazine. In early 1940 twin-gun 37 mm mounts replaced the single-gun mounts and in October–November a pair of Browning 13.2-millimeter anti-aircraft machine guns were installed on the quarterdeck. In 1941–1942 the quarterdeck guns were transferred to positions forward of the bridge and the Hotchkiss machine guns were repositioned on new platforms on the center superstructure. L'Indomptable had the aft superstructure remodeled in 1941 to create a platform atop the aft ammunition hoists and platforms on each side for 37 mm guns. The twin-gun mounts was repositioned on the upper platform and one of the lower platforms while the other one was occupied by a single mount as there was a shortage of twin-gun mounts. In 1942 the ship was provided with an Alpha-2 sonar system in cases, pending the modification of the hull to accommodate the required flexible underwater dome scheduled for the following year.[5]

When the Le Fantasques entered service they were assigned to the newly formed 8th and 10th Light Divisions (Division légère) which were later redesignated as scout divisions (Division de contre-torpilleurs); both divisions were assigned to the 2nd Light Squadron (2eme Escadre légère) in Brest. On 12 May 1936, L'Indomptable and the submarine Pasteur collided at the mouth of the Gironde during an exercise of the 2nd Light Squadron.[6] Albert Lebrun, President of France, inaugurated the new building of the Naval Academy (École Navale) in Brest and reviewed the 2nd Light Squadron — including L'Indomptable, L'Audacieux, Le Fantasque, and Le Terrible— on 30 May 1936.

As of 1 October 1936 L'Indomptable, Le Triomphant and Le Malin were assigned to the 8th Light Division while Le Fantasque, Le Terrible and L'Audacieux belonged to the 10th.[7] Between 15 January and 26 February 1937, the 2nd Light Squadron cruised as far south as Conakry, French West Africa. On 27 May, Alphonse Gasnier-Duparc, Minister of the Navy, reviewed the fleet, including all of the Le Fantasque's.[8]

Both the 8th and 10th Scout Divisions were assigned to the Force de Raid when war was declared in September 1939; it made only a single sortie as a complete unit on 2–6 September when it responded to an erroneous report that German ships had left port. Afterwards it was dispersed into smaller groups to search for German commerce raiders and blockade runners.[9] During 21–30 October, the Force de Raid, including all of the Le Fantasques, screened Convoy KJ 4 against a possible attack by the heavy cruiser Admiral Graf Spee. On 25 November the 8th Scout Division, which consisted of L'Indomptable, Le Malin, and Le Triomphant, rendezvoused with the battleship Strasbourg and escorted her to Brest.[10] In anticipation of an Italian declaration of war, the Force de Raid, including the 8th Scout Division, assembled in Mers-el-Kébir, French Algeria, on 5–9 April, only to return to Brest when the Germans invaded Norway on the 10th. On the night of 23/24 April 1940, the 8th Scout Division made a high-speed patrol of the Skaggerak, hoping to attack German merchantmen headed for Norway. They encountered two patrol boats and damaged one of them while also engaging a pair of S-boats to little effect and narrowly missed spotting a convoy of minelayers. Le Malin then began having engine problems and the ships were forced to reduce speed. Near-misses by German bombers damaged one of Le Triomphant's propeller shafts as they withdrew. L'Indomptable and Le Malin returned to Mers-el-Kébir on 9 May, but transferred shortly afterwards to nearby Algiers. She took part in a sortie by the Force de Raid into the Western Mediterranean on 12–13 June, after Italy declared war on the Allies on the 10th. L'Indomptable then began escorting convoys evacuating people from mainland France to French North Africa, and escorted cruisers fruitlessly searching for Italian cruisers on 23–24 June after an erroneous report that they were at sea. After the British attack on Mers-el-Kébir on 3 July, the ship escorted the cruisers that attempted to rendezvous with Strasbourg after she escaped from Mers-el-Kébir and later arrived at Toulon.[11]

A view of Toulon harbor, late 1944, looking down the length of the Quai Noël. From left to right, Tartu, Cassard and L'Indomptable (all sunk upright), Vautour (nearly fully submerged) and Aigle (capsized and blown in two). In the right center distance is the partially dismantled old battleship Condorcet.

When the Forces de haute mer was formed on 25 September, L'Indomptable was the only ship of her class assigned to it and was one of its escorts when they made a training sortie into the Western Mediterranean on 16–18 October. When the Germans attempted to capture the French ships in Toulon on 27 November 1942, the ship was scuttled by her crew. The Germans considered salvaging her and redesignated her as SG9, but the ship was badly damaged during Allied bombing raids on 4 February, 7 March and 29 April 1944 and she was deemed a constructive total loss. L'Indomptable's bow was salvaged in July 1945 and was used to replace the bow of Le Malin which had been severed in a collision with Le Terrible. L'Indomptable's wreck was scrapped in place in 1950.[12]