Early in they had overrun Yugoslavia and had passed on to the invasion of Greece. At sea, the situation was bad and getting worse. Mercantile losses had been mounting ever since the fall of France. By May, , they had become so serious that the British War Cabinet was on the point of deciding that it would be contrary to the national interest to publish any more monthly figures of the tonnage sunk.
The Scheer had been operating against shipping in the Atlantic late in The battle cruisers Scharnhorst and Gneisenau had been out early in and had inflicted some severe losses on convoys before appearing at Brest in March. It was almost certain, too, that the new battleship Bismarck had been completed and had for some months been under training in the Baltic.
She also might take a hand in the game at any time. In the early hours of May 21, a report arrived in the Admiralty to the effect that two large German warships, heavily screened and accompanied by eleven merchant vessels, had been seen steaming northwards in the Kattegat the day before. This vital piece of news was at once sent on to the flagship of the Home Fleet, H. The information that had just come in was obviously of major importance, though not such as to cause surprise.
Two questions immediately arose: What were these enemy ships that had been seen coming north, and what were they going to do? It was, of course, a matter of conjecture whether the Bismarck was one of the German squadron. But this assumption was, in fact, made from the start-that the Bismarck was coming out. There had been indications for some days that some enemy operation might be imminent.
In the second week of May, an unusual amount of German air reconnaissance had been noticed between Jan Mayen Island and Greenland; that is, over the sea approaches to Iceland from both east and west. As there was also a noticeable increase in enemy aerial reconnaissance over Scapa, a circumstance which usually presaged a German naval enterprise of some kind, Sir John Tovey, with the possibility of an enemy movement ever in the forefront of his mind, had signaled to the cruiser Suffolk, then on patrol in the Denmark Strait to the north of Iceland, to keep a special watch on the passages in both directions.
