It was the duty of HMS Hood to engage the enemy, and there were three good reasons why she was committed to battle against Germany’s Bismarck in May 1941.

The first is simply that the Admiral-class Hood was the fastest battleship in the British fleet. Most British battleships were too slow to catch Bismarck: even the new King George V-class ships were three to four knots slower. With a top speed of 31 knots and a displacement of 47,000 tonnes, Hood could shoulder her way through any sea state and had a one-knot advantage over her German rival.

The second reason is that Hood’s shortcomings in armour were well understood and were not sufficient to keep her home. She had 12 inches of armoured plate along her main belt, just three inches less than the new KGVs. It did thin out toward the bow and stern, and between the main belt and the main deck. That left her vulnerable, but it was adequate, barely. Her deck armour was weak, “spaced” in a series of two- and three-inch armoured decks designed to handle shells coming in at a fairly flat trajectory. Everyone knew she was not proof against plunging fire, but few battleships were.

Vice-Admiral Lancelot Holland’s tactics compensated for Hood’s weaknesses. He pushed her as quickly as possible through the zone of plunging fire at maximum range, and into what the Americans called the “Immune Zone”—that place where both the deck and side armour stood a chance against enemy fire.

Arguably, Holland achieved his goal. Hood had reached roughly 15,000 metres range when Holland turned her broadside, presenting her heaviest armour and allowing her rear turrets to fire. At this range, Bismarck’s fire would have struck Hood’s deck at an angle of about 14 degrees, too shallow even by German estimates to pierce the deck. Destruction appears to have come from a shell that penetrated Hood’s side, either right through her 12-inch armour, or perhaps just above it, and detonated one of her magazines. Those things happen. A few more minutes, with all of Hood’s and HMS Prince of Wales’s main armament—eight 15-inch and ten 14-inch guns—focused on Bismarck, and things might well have gone differently.

The third reason why it was necessary to send Hood out to find Bismarck is simply that the British had too few battleships: only 14 in May 1941. The four small R-class battleships were even older than Hood and were no match for a modern battleship. The five rebuilt Queen Elizabeth-class ships were based in Alexandria, Egypt, watching the Italian navy. Of the two lumbering Nelson-class ships built under treaty restrictions in the 1920s, HMS Rodney was en route to the United States for a refit and HMS Nelson was in Freetown, Sierra Leone, after escorting a troop convoy. The best of the RN’s battlefleet, two newly commissioned King George V-class battleships—42,000 tonnes, 28 knots—and Hood were at Scapa Flow watching for Bismarck.

Hood had to go. With luck, she might have survived the Battle of the Denmark Strait. As things turned out, Bismarck suffered enough damage in the action to force her into the waiting Fairey Swordfish torpedo-strike aircraft of HMS Ark Royal—and an end sealed by an even more improbable bit of bad luck.

The Battle of the Denmark Strait was barely eight minutes old when the inside of HMS Prince of Wales’ gunnery control position was brightly illuminated, as if by a brilliant sunset or sunrise.

Too busy to see why, the battleship’s gunnery officer, Lieutenant-Commander Colin McMullen, kept his focus on trying to hit Bismarck. In fact, the bright light was from HMS Hood blowing up, with her bow rising vertically in the air and the twin 15-inch guns of A turret firing one last defiant salvo. Sailors and marines in the shadowing cruiser HMS Suffolk, witnessing the horrifying turn of events from some kilometres distant, found it almost incomprehensible.

With the benefit of hindsight, the generally accepted verdict is that, yes, it was wrong for Hood, a battlecruiser of First World War vintage, to have been sent to fight the modern, heavily armed and protected battleship Bismarck. It would have been better if Hood had been decommissioned many years earlier and replaced with a modern, faster and better-armoured battleship.

However, the British had no choice but to send Hood out. Their navy was still the most powerful in the world, but it was stretched by operations across the oceans, not least convoy escort work in the Atlantic.

In pondering how best to position his ships to intercept Bismarck’s breakout, Home Fleet commander Admiral John Tovey—aboard his flagship, HMS King George V, at anchor in Scapa Flow—decided to send a hunting group composed of Hood and Prince of Wales toward Iceland. This was to potentially carry out an interception, either in the Denmark Strait or Iceland-Faroes gap.

Tovey’s decision was shaped by a failure to intercept German surface raiders a few months earlier. Back then, on receiving a similar raider alert, he had deployed with the entire Home Fleet to cover a potential breakout point south of Iceland.

He soon realized he had made a major error, because when fuel ran low there were no major units in reserve. The Home Fleet withdrew and Gneisenau and Scharnhorst slipped through into the North Atlantic to cause havoc in the shipping lanes.

This time, Tovey intended to retain enough hitting power at Scapa to respond to events as they unfolded. King George V would be connected through the landline to the Admiralty as long as possible in order to receive the latest information from the Navy’s operational centre.

Should Bismarck evade Hood and Prince of Wales, Tovey would take King George V and the carrier HMS Victorious, plus assorted cruisers, with him to try to intercept the Germans elsewhere.

Tactically, therefore, Tovey made the right decision. With available capital ships scarce, he combined the new, well-protected and fast battleship Prince of Wales—unblooded and experiencing problems with her complex 14-inch guns—with the harder hitting and already combat-proven 15-inch guns of Hood.

In terms of potential sacrifice, it was part of the deadly game. After nearly two years of bloody war, thousands of men had already paid the price, the Luftwaffe was simultaneously hammering the Mediterranean Fleet off Crete, and British sailors were used to facing tricky situations. So, even though Bismarck outmatched her one-on-one, the real question is why in the world would Hood have been held back?