Scapa Flow is the vast natural harbour enclosed by Hoy, Mainland, South Ronaldsay and the smaller Orkney islands - around 125 square miles of sheltered deep water, with narrow entrances easily defended. The Royal Navy chose it as its main northern fleet base in 1914, and in 1915 the cemetery at Lyness opened to receive its first burials. From here the Grand Fleet sailed to fight at Jutland in 1916, the largest naval battle of the First World War. In 1916, returning from Russia, HMS Hampshire struck a mine off Marwick Head and sank with Field Marshal Lord Kitchener aboard - 737 men lost, only twelve survivors. In 1917 HMS Vanguard exploded at anchor in Scapa Flow during the night of 9 July from a magazine accident, killing 843. Eighteen of Vanguard's dead are buried at Lyness.

On 21 June 1919, after months of internment in Scapa Flow following the Armistice, the German High Seas Fleet was scuttled by its own crews on the orders of Admiral Ludwig von Reuter. Without warning, the seacocks were opened across the fleet. Fifty-two warships - battleships, battlecruisers, cruisers, destroyers - settled to the seabed in the largest single mass scuttling in naval history. Nine German sailors were killed during the scuttle, shot by British guards or drowned in the confusion; they lie in Lyness too. In the 1920s the salvage firm Cox and Danks set up its headquarters at Lyness and began the extraordinary work of raising the warships from the bottom of the Flow. Many were brought up and scrapped. Some still lie there, slowly rusting away, dived today by sport divers.

On the night of 14 October 1939, six weeks into the Second World War, the German submarine U-47 commanded by Gunther Prien threaded through the eastern defences of Scapa Flow and torpedoed the battleship HMS Royal Oak at her moorings off Gaitnip. The ship rolled and sank within thirteen minutes. Of the 1,234 men aboard, 835 died - among them 134 boy seamen aged sixteen and seventeen, sleeping in their hammocks when the torpedoes struck. The wreck lies on the seabed of Scapa Flow now, designated a war grave, oil still occasionally seeping to the surface. Twenty-six of the Royal Oak's dead are buried at Lyness. After the attack the Churchill Barriers - concrete causeways linking the southern islands - were built to close the eastern channels for good. HMS Proserpine became the official name of the wartime Lyness base. It remained the main Royal Navy facility in Scapa Flow until the base closed in 1946.

The roll at Lyness is precise. 445 Empire and Commonwealth service personnel from the First World War - 109 of them unidentified, the gravestones marked simply as known unto God. 200 from the Second World War, eight unidentified. Fourteen German Navy sailors. Four other German service personnel including an unidentified Luftwaffe airman shot down over Orkney. One Norwegian war grave. Thirty British non-war service burials. The graves run in neat rows up the hillside above the village, set against a backdrop of moor and sea. The Commonwealth War Graves Commission maintains the site as it does every such cemetery, the white headstones impeccable in the wind. Lyness is rarely crowded. The visitors who make it here tend to come quietly, and stay a while.

The naval base is gone, the great fuel oil tanks mostly demolished, the buildings either repurposed or in ruin. Lyness today is just a few houses, the ferry pier with its waiting room, and a small museum. The Orkney Ferries Ro-Ro ferry from Houton on Mainland calls here several times a day, linking Lyness with the rest of Orkney. In 2010 and 2011 the Golden Wharf at the harbour was upgraded to host renewable energy projects - the Pelamis wave converter and the Wello Penguin among them - a quiet pivot from the old naval economy to a possible future one. Emily's Tea Room half a mile up the road serves lunch in season. The cemetery is open at any hour, and is the reason most visitors come. The Flow itself, half a mile east, remains as it always was - calm, vast, quietly holding its dead.