Aboard the South African warship Amatola, everyone has a role and a pair of words to describe it. The buffers make sure the vessel is “spick and span,” the engineers keep it “up and running,” and the communications team is its “eyes and ears.” On a bright summer morning in January, a few days before the Amatola was to set sail from Simon’s Town Navy Base, south of Cape Town, the ship was bustling. In the officer’s mess, men in their dress whites served themselves an early lunch from platters piled high with baloney and egg-salad sandwiches; for dessert, there were cheerful little scones, halved and topped with jam and whipped cream. Outside, in a passageway, young men and women carried crates of beer, Coca-Cola, and cider to a man with a clipboard, who ticked the supplies off a list, whistling. On the other side of the far passageway wall, Lieutenant Commander Sipho Ngema, an engineer, sat in his quarters. Behind him, on the bottom bunk of the bed he would sleep in for the next three months, a floral duvet waited to be unrolled. Ngema, a nine-year veteran of the South African Navy, recalled the day he came down from Pretoria for basic training. It was the first time he had ever seen the ocean. “It was a very scary thing,” he said. “You always get stories about the sea being dangerous—that it can take you away.”

The Amatola was scheduled to put out from Simon’s Town on January 16th. After five weeks patrolling African waters for pirates and participating in exercises with the British and German navies, it would reach a position in the English Channel just south of the Isle of Wight, where it would lay a life buoy decorated with flowers on the water in memory of the S.S. Mendi, a passenger steamer that sank there in 1917. The Mendi is one of South Africa’s most celebrated military legends. February 21st, the day the ship went down, has been declared Armed Forces Day, and the country’s highest decoration for bravery is called the Order of Mendi. The medal has a border of lion-paw prints, signifying vigilance and power. At its center, above an image of the foundering vessel, is a blue crane in flight, which represents the departing souls of the dead. Generations of South Africans have told and retold the story of the Mendi, such that the details are both essential and pliable. The standard version, though, goes something like this.

Hours before sunrise on the fatal day, the Mendi was motoring slowly through a thick fog, escorted by the British destroyer H.M.S. Brisk, which provided protection from German U-boats and mines. Belowdecks, the passengers—men on their way to the First World War—slept in their uniforms and coats to keep warm, their heads resting on life preservers. They were members of the South African Native Labour Contingent, a corps of twenty-one thousand black men recruited by the Allies to load and unload cargo in French ports, to quarry and build roads, to cut timber and repair railways. Like their counterparts from Egypt and China, the South African workers were explicitly barred from bearing arms or fighting alongside white soldiers.

At 4:57 A.M., the bow of the Darro, a cargo ship twice the Mendi’s size, slammed into the smaller vessel’s forward hold at a right angle. Despite the weather, the Darro had been travelling at full speed, likely trying to clear the dangerous waters of the Channel before daylight, and had spotted the Mendi too late to avoid it. Jacob Matli, lying in bed after his shift in the Mendi’s boiler room, immediately made his way to the outer deck. There, in the dark, men from his company stood to attention, waiting for orders. Matli searched for someone who could tell them what to do. He approached a white captain and asked him for help, but the man did not respond. Matli returned to his comrades, who were now struggling to untie the ropes on a life raft. (The ropes were designed to be cut.) Then he went back to the captain, who without a word descended a staircase. A few moments later, there was the sound of a single gunshot.

Matli jumped overboard. He swallowed water, came up for air, and saw, illuminated for a moment by a searchlight—possibly from the Brisk, or from another ship, the Sandsend, or from the Darro itself—a group of men holding onto a life buoy. He swam toward them. When they wouldn’t give him space, he clambered onto someone’s back. Then Matli, soon to be rescued by the Sandsend, watched the Mendi submerge. “As it sank it made a great hollow and many men were not far from it,” he later wrote. “By the time the water covered that empty space, many had gone down with it.” Within twenty minutes of the collision, the Mendi was underwater, along with six hundred and forty-six of its passengers—thirty crew, nine officers, and more than three-quarters of the eight hundred laborers aboard. But shortly before it sank, the story goes, a black writer, activist, and pastor, Isaac Dyobha, called out to the men too afraid to jump overboard:

Be quiet and calm, my countrymen, for what is taking place now is exactly what you came to do. You are going to die, but that is what you came to do. Brothers, we are drilling the drill of death. I, a Xhosa, say you are all my brothers. Zulus, Swazis, Pondos, Basutos, we die like brothers. We are the sons of Africa. Raise your cries, brothers, for though they made us leave our weapons at our home, our voices are left with our bodies.

It is said that the men still aboard the Mendi danced in unison, stamping a rhythm on the deck with their bare feet.

The bodies that were recovered from the water that morning, along with those that washed ashore in England, France, and the Netherlands in the following weeks, were buried in cemeteries and churchyards close to where they were found, sometimes in communal graves. The survivors, for the most part, were also treated ingloriously. In the months before the Mendi left port, South Africa’s black leaders had actively supported the government’s recruitment campaign; many had signed up for the labor contingent themselves, hoping that their participation would help them argue for equal rights once the war was over. Instead, when they returned, their work was barely acknowledged, much less rewarded. Not one member of the contingent, not even survivors of the Mendi, got so much as a ribbon or a medal. They weren’t paid pensions, nor did they receive promised grants of land or cattle. A. K. Xabanisa, a veteran of the contingent, later wrote, “I am just like a stone which after killing a bird, nobody bothers about, nobody cares to see where it falls.”