The modern era of amphibious operations is usually identified to have begun with the invasion of Gallipoli during WWI. The Allies were attempting to open a sea route to Russia though the Turkish Straits between the Mediterranean and Black seas. Their initial naval assault had failed badly,1 so a plan was made to land troops to silence the guns protecting the strait.
Unfortunately, the allies did almost everything wrong. The plan and equipment had to be improvised in the month between the decision to go ashore and the actual landing in April of 1915. No serious planning had been made for large-scale amphibious operations before the war, and the five divisions assembled,2 despite representing some of the best troops available, were insufficient for the job. Like so many invasions before, this one was made in boats rowed ashore. The only specialized landing ship, River Clyde, was a converted collier intentionally grounded near Cape Hellas.3 The Ottomans near the beach were insufficient to throw back the landing force, but they inflicted savage casualties due to the lack of fire support and the general chaos. The commanders had not given sufficient emphasis to the need to move inland and the allied advance, like that of the Persians millennia before, bogged down, giving the Turks time to respond.
The first modern landing craft, the "X Lighter", was used during the landing at Suvla Bay in August. Built to hold 500 men each and armored against machine-gun fire, and fitted with a bow ramp to allow rapid disembarkation, they would set the pattern for future landing craft. Unfortunately, the British had learned little else, and the Sulva Bay landing failed due to lethargy on the beaches, much as the earlier landings had.
The forces at Gallipoli remained perched in their narrow, craggy positions for 8 months, fighting viciously with the Ottomans. Finally, on January 8th, 1916, the last troops were withdrawn. The failure of the operation was a major scandal, and its greatest proponent, Winston Churchill, had to resign as First Lord of the Admiralty.4 The biggest amphibious operation by the Central Powers was Operation Albion, part of the German assault on the Gulf of Riga.
During the interwar years, tacticians, most notably with the US Marine Corps, attempted to digest the lessons of Gallipoli. The Marines faced a daunting challenge. In the event of the most likely war, that with Japan, they would be responsible for securing islands across the Pacific to support the American advance, and they would have to land in the teeth of Japanese defenses to do it. So they began to make plans.
The first major amphibious operation of World War II was the Norwegian Campaign. This was interesting, as the German invasion of Norway barely beat the British and French, who were planning to do the same thing. Despite an overcomplicated plan with 11 separate landings, the Germans seized all but the northern section of the country, where the British annihilated their naval force at Narvik, then landed troops to retake it.5 However, the Kriegsmarine took heavy losses, most notably the new heavy cruiser Blucher.
One aspect of amphibious warfare is withdrawing forces across a beach, which most famously happened at Dunkirk, when the British withdrew their troops from France. 338,000 men were evacuated using anything the British could lay hands on, from destroyers down to civilian excursion boats. Ultimately, 85% of the men trapped against the Channel were evacuated to the UK, although they had to abandon everything heavier than their personal weapons.
With the British forced off the continent, Churchill ordered preparations for a cross-channel invasion, which eventually lead to many of the ships critical to the amphibious assaults that dominated the last two years of the war. Hitler also ordered preparations for his forces to cross the Channel. In practice, the German General Staff responded by ordering their subordinates to produce paperwork for Operation Sea Lion, then going to lunch with French models. A cross-channel invasion would have been a near-impossible undertaking even if the Germans had miraculously secured sea and air superiority. They planned to make their invasion on converted coastal barges, which could have been attacked by British destroyers steaming by at high speed to swamp them. As the generals probably expected, Hitler eventually got bored and decided to attack Russia instead.6
The Japanese were leaders in amphibious warfare during the interwar years, and their conquest of the Far East had a major amphibious component. Their doctrine emphasized striking quickly at unopposed beaches, often using warships as transports, and it worked well across most of the Pacific. The only assault that was staunchly resisted was their attempt to take Wake Island, where the first landing was beaten off by gunfire from the Marines ashore before the second took the island. Their most notable innovation was the landing craft carrier, a ship designed to carry landing craft internally and then launch them by flooding an internal well deck.
The US struck back surprisingly quickly with the landings on Guadalcanal in August 1942. Mostly unopposed on land, the threat of the Japanese surface fleet forced the ships to withdraw before they'd unloaded all of their supplies. The result was a 6-month campaign where the Japanese repeatedly tried to throw the Marines into the sea, and the Marines doggedly held on, then gradually pushed out to secure the rest of the island.
Less than two weeks after the Marines landed on Guadalcanal, to gain experience for the invasion of Europe, the British and Canadians staged a major raid at Dieppe. They believed that it would be necessary to capture a port on the first day of the assault to allow supplies to flow ashore. The raid was a complete disaster, over 60% of those going ashore being either killed, wounded, or captured, in large part due to difficulties getting tanks ashore to support the infantry. Better vessels would be needed for that.
That November, the allies invaded French North Africa, modern-day Morocco and Algeria. It was hoped the French would welcome the Americans ashore, but they put up resistance, more so in some areas than others. This operation held the distinction of being the longest-ranged of the war, with some of the American units sailing directly from the continental US. Despite the rather messy landings, the allies did succeed in getting a foothold in North Africa, taking the Axis forces fighting in Libya and Egypt from behind, and eventually forcing them out of Africa altogether. The difficulty of taking ports directly from the sea during this operation, combined with the failure at Dieppe, convinced them that future invasions would need to be supplied directly across the beach.
Throughout 1943, the allies made a number of landings. The Americans began the slog up the Solomon Islands, slowly getting closer to the Japanese base at Rabaul. In New Guinea, a new type of amphibious warfare was developed, where troops were embarked in the landing craft and taken directly to the beach, known as shore-to-shore, as opposed to the more typical ship-to-shore invasion. In July, the allies landed in Sicily with eight divisions, setting a record for the largest assault force of any amphibious invasion, and quickly overrunning the island.7 In September, the allies went ashore at Salerno, Italy. This invasion was not particularly successful, as they were expecting to meet only Italians, in the process of surrendering, and instead ran into German resistance that stalemated them for almost a year.
Next time, I'll look in detail at the Tarawa invasion, which shows most of the innovations made by the allies during the war.
1 This is mentioned in Mine Warfare Part 1, and I might describe the operation in more detail some day. Interestingly, there were a few very small landings to demolish forts made as part of the early attacks, which seem to have gone well. ⇑
2 One of pre-war British troops, two of Australian and New Zealander troops, one French, and one from the Royal Navy. ⇑
3 Some forces landed at Cape Hellas, others, mostly Australian and New Zealander, at ANZAC Cove. ⇑
4 Contrary to popular belief, it didn't almost end his career. He regained office as Minister of Munitions in the summer of 1917, which is about what you'd expect of a rising star who had to be scapegoated for a failure. ⇑
5 Narvik was eventually evacuated after the fall of France, when the naval commitment to hold it would have overstressed British resources. ⇑
6 Any attempts to justify the unmentionable marine mammal will be mocked. The last attempt I saw to salvage it suggested that the Germans should have seized the Isle of Wight, which would have allowed them to interdict the British naval base at Portsmouth with artillery. The author seems to have not noticed the base before the Germans got ashore, and the biggest question is if the RN cruisers would have had to leave port to stop the landing, or if they could have thwarted it by firing from their berths. ⇑
7 Yes, this does include Normandy, which had a 6-division assault force. ⇑