RMS Carinthia was first laid down in Barrow-in-Furness in 1924 with the yard number Hull 586. Originally she had the name Servia but was renamed at the time of her launching on 24 February 1925. She made her maiden voyage on 22 August 1925 from Liverpool to New York City. At her launch she was the largest of the five post First World War intermediate size liners.

The Northern Patrol, also known as Cruiser Force B and the Northern Patrol Force, was an operation of the British Royal Navy during the First World War and Second World War. The Patrol was part of the British "distant" blockade of Germany. Its main task was to prevent trade to and from Germany by checking merchant ships and their cargoes. It was also to stop German warships, raiders and other German naval ships from leaving the North Sea for the Atlantic Ocean or entering the North Sea from the Atlantic, protect Shetland against invasion and to gather intelligence from intercepted neutral ships.