Learn about this topic in these articles:
World War I
- In 20th-century international relations: Attitude of the United States
…4, 1915, Germany declared the waters around the British Isles a war zone in which Allied ships would be sunk, without warning if necessary. While this procedure dispensed with traditional civilities like boarding, search and seizure, and care of civilians, effective submarine warfare required it. Underwater craft relied on stealth…
Read More - In World War I: The war at sea, 1914–15
…to rely entirely on the submarine.
Read More - In World War I: German strategy and the submarine war, 1916–January 1917
…a tentative reopening of the submarine campaign on February 4, 1916, the German naval authorities in March gave the U-boats permission to sink without warning all ships except passenger vessels. The German civilian statesmen, however, who paid due attention to their diplomats’ warnings about U.S. opinion, were soon able to…
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World War II
In both world wars, submarines were also a serious threat to merchant shipping. In World War II, German U-boats nearly severed the lifelines to Great Britain, U.S. submarines successfully isolated Japan by nearly wiping out its merchant fleet, and, in the Mediterranean, British and Axis submarines vied in attempts…
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Historic England is marking the centenary of Germany’s declaration of unrestricted submarine warfare (1st February) by sharing never before seen images of German submarines, newly acquired by the Historic England Archive.
The national memorial to submariners has also been upgraded to II* by the Department for Culture, Media and Sport on the advice of Historic England.
New to the Archive
The collection of images shows German submarines, known as U-boats, wrecked on the Cornish coast in Falmouth.
The submarines had been surrendered by Germany after the war ended in 1918 and were on their way to be sunk as gunnery targets. But stripped of their engines, submarines were difficult to tow and occasionally sank or wrecked on Britain’s beaches, as in the case of the Falmouth U-boats.
The photographs were taken in 1921 by the notable naval officer Jack Casement on what was probably his last official posting before he retired. They were donated to the Historic England Archive by Casement’s family.
They offer us a rare insight into official military business after the war, through the eyes of a distinguished veteran of the First World War at sea.
What was unrestricted submarine warfare?
Germany declared unrestricted submarine warfare for the second time on 1st February 1917 and began torpedoing ships without warning, meaning passengers and crew had no chance of escape.
Nicknamed Der magische Guertel, or the magic girdle, the aim was to strangle Britain to the brink of starvation and desperation by stopping both supplies getting in and exports getting out.
All ships trading with Britain were seen as targets by the Imperial German Navy, including those from neutral countries such as Norway, Denmark and the United States. The targeting of American ships ultimately brought the United States into the war in April 1917.
Even hospital ships were targeted by German forces during unrestricted submarine warfare, provoking worldwide outrage. Ships like the Rewa, torpedoed in 1918, were unarmed and painted with the internationally recognised symbol of the Red Cross but were still targeted.
The impact
Despite some interesting solutions to combat the U-boat attacks, from travelling in convoys to dazzle camouflage which broke up the outlines of ships, making their direction of travel more difficult to see, the losses were huge.
During 1916, 431 British ships were sunk by German U-boats worldwide but in 1917 following the declaration of unrestricted submarine warfare, the number lost nearly tripled to 1263.
A memorial to submariners
The National Submariners memorial by Frederick Hitch at Temple Pier on the Thames has also been upgraded to II*. It is an eloquent memorial unveiled in 1922 to the many submariners who died in active service.
A third of the Submarine Service’s total personnel lost their lives during the First World War – the highest proportion of any branch of the armed services.
Oddly, the memorial shows a cross-section of a submarine, ensnared by watery allegorical figures.
This part of the Thames is associated with submarines. There are records of British submarines moored near Temple Pier in 1907, and in August 1916 a German U-boat captured off the Suffolk coast was moored here as a visitor attraction.
Roger Bowdler, Director of Listing at Historic England said: “The declaration of unrestricted submarine warfare in February 1917 was a decisive moment in the First World War. Germany’s tactic led to devastating losses for many nations but it also horrified the world.
It was seen as uncivilised, ungentlemanly and ultimately brought the might of the United States into the war. By commemorating this day we can better understand its consequences and remember the many people who lost their lives in this way.”