Following the French surrender and armistice with Germany, the British were concerned that Germany may gain control of the French navy, adding their fleet to the Kreigsmarine would tip the naval balance of power in the Axis’ favour resulting in additional difficulty in receiving supplies vital to continue the war.
The British government feared the possibility despite the fact that the Armistice terms at Article 8 paragraph 2 stated that the German government “solemnly and firmly declared that it had no intention of making demands regarding the French fleet during the peace negotiations” and similar terms existed in the armistice with Italy. Furthermore, on 24 June, Admiral Darlan had given assurances to Churchill against such a possibility. However Churchill ordered that the French Fleet should either turn themselves over or be neutralised.
The fleet were dispersed in various ports in the mediterranean and in Portsmouth and Plymouth. Those ships were simply boarded during the night of the 3rd, although the French put up limited resistance resulting in the deaths of 3 Royal Navy personnel and one French sailor.
On July 3, 1940 the greatest concentration of French ships were at the port of Mers-el-Kébir, Algeria. Force H consisting of the carrier HMS Ark Royal and accompanied by the battlecruiser HMS Hood, Battleships HMS Valiant and HMS Resolution and accompanying destroyers and cruisers. On arrival the commander of force H, Admiral James Somerville delivered the ultimatum to the commander of the French Fleet:
It is impossible for us, your comrades up to now, to allow your fine ships to fall into the power of the German enemy. We are determined to fight on until the end, and if we win, as we think we shall, we shall never forget that France was our Ally, that our interests are the same as hers, and that our common enemy is Germany. Should we conquer we solemnly declare that we shall restore the greatness and territory of France. For this purpose we must make sure that the best ships of the French Navy are not used against us by the common foe. In these circumstances, His Majesty’s Government have instructed me to demand that the French Fleet now at Mers el Kebir and Oran shall act in accordance with one of the following alternatives;
(a) Sail with us and continue the fight until victory against the Germans.
(b) Sail with reduced crews under our control to a British port. The reduced crews would be repatriated at the earliest moment.
If either of these courses is adopted by you we will restore your ships to France at the conclusion of the war or pay full compensation if they are damaged meanwhile.
(c) Alternatively if you feel bound to stipulate that your ships should not be used against the Germans unless they break the Armistice, then sail them with us with reduced crews to some French port in the West Indies — Martinique for instance — where they can be demilitarised to our satisfaction, or perhaps be entrusted to the United States and remain safe until the end of the war, the crews being repatriated.
If you refuse these fair offers, I must with profound regret, require you to sink your ships within 6 hours.
Finally, failing the above, I have the orders from His Majesty’s Government to use whatever force may be necessary to prevent your ships from falling into German hands.
However the commander of the French fleet omitted all the terms other than the scuttling of the ships.
Before negotiations were formally terminated, British Fairey Swordfish planes escorted by Blackburn Skuas were dispatched from the Ark Royal to drop magnetic mines in the path of the French ships’ route to sea. This force was intercepted by French Curtiss H-75 fighters. One of the Skuas was shot down by French fighters and crashed into the sea, killing its two-man crew, the only British fatalities in the action.
The British opened fire at extreme range on 3 July 1940 at 17:54. The French eventually replied but ineffectively. The third salvo from the British force and the first to hit resulted in a magazine explosion aboard Bretagne, which sank with 977 of her crew dead. Provence, Dunkerque and the destroyer Mogador were damaged and run aground by their crews.
Strasbourg managed to escape with four destroyers. As these five ships made for the open seas, they came under attack from a flight of bomb-armed Swordfish from Ark Royal. The French ships responded with antiaircraft fire and shot down two of them, and their crews were rescued by the destroyer HMS Wrestler. The bombing attack had little effect and Somerville ordered his forces to begin pursuing at 18:43. The British cruisers Arethusa and Enterprise reported engaging a French destroyer. At 20:20, Somerville called off the pursuit, feeling that his ships were ill-deployed for a night engagement. After weathering another Swordfish attack at 20:55 without damage, Strasbourg reached the French port of Toulon on 4 July.
On November 27 1942, German forces attempted to capture the remains of the French fleet at Toulon, Admiral Darlan true to his word scuttled the fleet to prevent this. Darlan wrote to Churchill stating:
“”Prime Minister you said to me ‘I hope you will never surrender the fleet’. I replied, ‘There is no question of doing so’. It seems to me you did not believe my word. The destruction of the fleet at Toulon has just proved that I was right.””
At Mers-el-Kébir, 1,297 French sailors were killed and about 350 were wounded compared to the two british fatalities. The attack left Anglo-French relations severely strained and many – including Somerville felt ashamed at their orders.