However, the realization of the scope of the U-boat campaign resulted in 111 being built.

Germany's U-boat campaign, the sinking of the Lusitania, turned public feeling against Germany.

As a result the Germans concentrated their U-boat campaign in the North Atlantic.

Only Britain held out - but on the brink of collapse, being strangled by Germany's U-boat campaign.

Despite heavy losses through our U-boat campaign and despite a 12,000-mile-long sea route, sufficient supplies for the British were getting through to the front.

After this failure they relied solely on the U-boat campaign, in which they had re-commenced unrestricted submarine warfare.

The largest and best known of them was Dönitz's U-boat campaign, aimed mainly against the United Kingdom.

From 1914 to 1918 more than 800 Norwegian merchant ships were sunk due to the German U-boat Campaign.

The way Dönitz conducted the U-boat campaign required relatively large volumes of traffic between U-boats and headquarters.

The sinking was part of the German U-boat campaign in the Indian and Pacific Oceans.