Relations between the French and British radically altered following the French armistice with Germany. Churchill was determined that the French Fleet should not fall into the hands of the Germans. The British Force H was sent from Gibraltar to confront the main French fleet in harbour. Admiral Somerville, commander of Force H, had orders to seek the French Fleet’s surrender at the French North African maritime base of Mers el Kebir at Oran, French Algeria. The terms contained a number of options designed to allow the French an honourable course of action while denying the French fleet to the Germans, these were:
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.
Admiral Somerville’s report describes how negotiations continued all day. He despatched Captain Holland to speak with the French Commander, Admiral Gensoul:
49. Whilst this long discussion was taking place in the Admiral’s cabin of DUNKERQUE, Admiralty message 1614/3rd July containing instructions to “settle matters quickly or you will have reinforcements to deal with” was received at 1646 in HOOD. A signal was immediately passed visually and by wireless to Admiral Gensoul, informing him that if the terms were not Accepted, fire would be opened at 1730. Simultaneously, “Preparative ANVIL at 1730” was made to all ships of Force “H”. (see para. 25 of Enclosure 3).
50. The message referred to reached Admiral Gensoul at 1715, whilst the discussion with captain Holland was still proceeding. The latter then drafted a brief signal, which was shewn to the Admiral, stating that the crews were being reduced and the ships would proceed to MATRINIQUE or the United States of America if threatened by the enemy. This was received in HOOD at 1729, but as it did not comply with any of the conditions laid down, air striking forces were ordered to fly off and the battleships stood in to the coast.
51. Captain Holland finally left DUNKERQUE at 1725 and at the same time “Action stations” were sounded in the French ships. Transfer to FOXHOUND’s motorboat was effected at 1735 and the boat proceeded clear of the net defences.
52. Fire was opened at maximum visibility range of 17,500 yards at 1754, employing G.I.C. concentration with aircraft spotting. The line of fire was from the north-west, so that fire from the French ships was to some extent blanked by Mers el Kebir Fort and risk of damage to civilian life and property reduced.
53. Simultaneously with opening fire, an aircraft report was received that the destroyers in Mers el Kebir were under way inside the boom.
54. At 1757, three minutes after opening fire, a very large explosion occurred inside the harbour, followed immediately by an immense column of smoke several hundred feet high. There would appear little doubt that this was caused by the blowing up of a battleship of the BRETAGNE Class. It was followed shortly after by a similar but smaller explosion which was apparently a destroyer blowing up. By this time, the harbour was clothed in smoke from explosions and fires, rendering direct spotting almost impossible and air spotting most difficult.
55. Enemy shore batteries opened fire about a minute after the first British salvo. These were promptly engaged by ARETHUSA but the range was too great for ENTERPRISE’s older guns. Shortly afterwards heavy projectiles commenced to fall near the battleships.
56. Enemy fire was at first very short but improved considerably in accuracy, a number of main armament (probably 13.4 inch) projectiles falling close to all ships and in certain cases, straddling. No hits were incurred, but a number of splinters caused minor superficial damage in HOOD and injuries to one officer and one rating.
57. After firing a total of thirty-six 15-inch salvoes, the fire from the French ships died down but the fire from the forts was becoming increasingly accurate. Course was altered 180 ° to port together and ships ordered to make smoke to avoid damage from the fire of forts. Fire on the French ships ceased at 1804.
See TNA ADM 199-391 for the full report and enclosures.
A French newsreel report of the action: