Wilhelm Rollmann was born on August 5, 1907 in (appropriately) the town of Wilhelmshaven. Entering into the German Navy (Reichsmarine) in 1926, as a Seekadett, Rollmann served in various capacities on various ships including the light cruiser Karlsruhe. In May 1937, he had impressively advanced all the way to the rank of Kapitänleutnant, and transferred to the U-Boat arm (Unterseebootewaffe). Following his training he was given command of U-34, a VIIA-class U-Boat, relieving Kptlt. Hans Pauckstadt.

In September 1939, during his first days at sea with U-34 and her crew, they managed to sink the 5,800-ton Puccastan and soon afterwards Kennebec, a 5,500-ton British tanker. October brought him four more attacks on ships. Some of the mine-laying missions of U-34 were also fruitful. On January 20, 1940 the 7,807-ton motor tanker Caroni River sank after hitting one of their mines. Eight days later the crew torpedoed and sank the ship Eleni Stathatos.

Rollmann and his crew sunk the British destroyer Whirlwind, one of the highlights of his career, in a war patrol in July. Two days afterwards, he destroyed an Estonian steamer, the Vapper, and soon after a small Dutch tanker. He had become a notable U-Boat captain by this time due to his success.

Between the 9th and 27th of July, 1940 Rollmann sank 9 ships, including the Accra, and Thiara, a 10,364-ton British motor tanker - bringing his scoresheet for this war patrol alone to 12 vessels. On the 31st of July, he was awarded the Knights to the Iron Cross for his success as a U-Boat commander.

After completing seven successful war patrols, Rollmann was moved to be an instructor at the 2. ULD (Unterseeboots-Lehr-Division - a U-Boat training unit) in the hopes of passing on his ability to future U-Boat commanders.

On the 20th of February, 1943 Rollmann was back in the U-Boat's, commissioning U-848, a large Type IXD2 U-boat, as a Korvettenkapitän. From 20 Feb, 1943 to 31 Jul, 1943 U-848 was used only in a training capacity for her crew under 4. Flotilla, until it was moved to 12. Flotilla on 1 Aug, 1943 and went out on a real war patrol. November 1, Rollmann was promoted to Fregattenkapitän. The next day it sank the 4,573 tons of the Baron Semple. However, four days later it was attacked from the air by Allied aircraft Southwest of Ascension Island. All 63 hands aboard went down with U-848.