Düppel (Schleswig-Holstein War).
This fortress, protected by an outer chain of ten redoubts, was invested by the Prussians, 16,000 strong, under Prince Frederick Charles, and the first parallel opened, March 30, 1864. The Danish garrison numbered 22,000. On April 17, after a heavy bombardment, the Prussians were launched at the first six of the chain of redoubts, and, after a brief resistance, they were captured and the place was immediately afterwards surrendered. The Prussians lost 70 officers and 1,331 men, the Danes, including prisoners, 5,500.