The German submarine U-156 was a Type IXC U-boat of Nazi Germany's Kriegsmarine built for service during World War II.

The incident led to the Laconia Order, banning U-boats from attempting rescues, and later caused major embarrassment to the US during the Nuremberg trials.

The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of 4,400 metric horsepower (3,240 kW; 4,340 shp) for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of 1,000 metric horsepower (740 kW; 990 shp) for use while submerged.

She conducted her first patrol from that same month, during which her crew trained, and at the end of which she arrived at her operations base in Lorient, France, in December 1941.

During its second patrol, U-156 participated in Operation Neuland, which intended to disrupt traffic in the Caribbean; and included an attack on the oil refinery at Aruba island, ordered by captain Hartenstein.

Von dem Borne was put ashore on the island of Martinique for medical treatment and survived the war.

After realising that the passengers were primarily POWs and civilians[2] the U-boat started rescue operations while flying the Red Cross flag.

A U.S. Army Air Corps bomber flying out of a secret South Atlantic airbase on Ascension Island attacked the U-boat.

This incident led to German Admiral Karl Dönitz issuing the Laconia Order on 17 September 1942, which forbade submarine commanders from rescuing survivors from torpedoed ships.

As a result of the second attack, on 8 March 1943, she was sunk approximately 280 nautical miles east of the island of Barbados, in position 12°38′N 54°39′W / 12.633°N 54.650°W / 12.633; -54.650, by a US PBY Catalina from VP-53 captained by Lieutenant E. Dryden.