The hills of Cumbria, in northern England, are known as fells. They are among the wettest, coldest, and windiest places where sheep are farmed outdoors year-round. The weather is rotten, more or less, from October to May. So by lambing season—a three-week period, usually after Easter, when the ewes give birth, and there are triumphs and miscarriages, adoptions and accidents, gambolling and suckling—the flock, the shepherd, and the land itself are already worn out. “You’re just about fucked,” James Rebanks told me. “The whole thing is designed so you are just about to break.”

On Twitter, Rebanks is the Herdwick Shepherd. A little more than a hundred and nine thousand people, most of them trapped in office environments or riding public transportation, follow his account for gorgeous, wide-skied pictures of his flock, and for his evocations of the English countryside. In 2015, Rebanks’s memoir, “The Shepherd’s Life,” became an international best-seller, and he was compared to the nineteenth-century rural poet John Clare. Clare, the son of illiterate laborers from Northamptonshire, wrote about the land from within it; Rebanks’s writing has a similarly involved quality. When he feeds his ewes, he writes, “They line up behind me, with their heads down, like a massive scarf.” Rebanks has around five hundred sheep to look after, and when they’re lambing he has no time to write. He barely sleeps. “You are trying to keep things alive,” Rebanks said. “You make a mistake and something dies. And then—if you get through it—in a week or ten days’ time, the grass comes, the sun shines, and there is a feeling of absolute sheer exhaustion that turns to elation.”

It was just before seven o’clock last Wednesday morning. Two-thirds of Rebanks’s ewes had lambed during the previous sixteen days. In theory, he was through the worst of it. We stood in a steel-framed barn on his farm, which is in the valley of Matterdale, in the Lake District. One side of the barn was open to the sky, which was gusty and full of rain. Inside, Rebanks, who is forty-three, had made temporary stalls for the ewes and newborn lambs that were struggling. Straw and wood chips covered the ground, and the air smelled of wet wool and new milk. “This is basically the hospital,” Rebanks said. He wore green waterproofs from head to foot. “Everything that is healthy and strong and big is outside.” There was a bashed-up table of shepherding accessories: bottles of lamb formula, a large knife, and a notch of sheep leg bone in a jar. Rebanks’s iPhone, which he uses to tweet, was charging on an extension cord.

Photographs by Gregor Schmatz for The New Yorker

Rebanks keeps two types of sheep: Herdwicks, a large mountain breed with blue-gray fleece that came to England with the Vikings, which he loves; and Swaledales, more obviously picturesque white animals with curling horns, which are slightly less hardy and which he is not so mad about. In one stall, two Herdwick lambs and their mother, which Rebanks had brought in from the rain, rested under a heat lamp. In another, a Swaledale ewe was unable to feed her lambs because she had no milk, so Rebanks fed them through a tube every four hours. If a lamb dies but its mother is able to raise an orphan, Rebanks cuts off the skin of the dead lamb and dresses the orphan in it so that the smell is familiar to her. Two black lambskins that he had used for this purpose lay discarded in the straw. Rebanks hopped in and out of the enclosures, picking up lambs to check their bellies for milk, and gently admonishing their mothers (“You can’t step on it”) as they fussed around him. “At the moment—touch wood—we are not losing many lambs,” Rebanks said brightly, and then paused. “That was a stupid thing to say.”

Lambing this year came after a hard winter. There were blizzards in northern England barely a month ago, and Rebanks’s sheep got sick with pneumonia and fluke. At one point he feared that twenty might die, though in the end only a few succumbed. “They are weaker than they should be,” Rebanks said, surveying the barn. In a good year, he has only five or six ewes and their lambs inside at any one time. On Wednesday, he had twenty-three. Mishaps, though, are part of every lambing season, and require Rebanks, who has no staff, to be in a dozen places at once. That morning, at dawn, one of his pregnant ewes, overcome with maternal instinct, had stolen a lamb from another sheep. Later, when she was giving birth to her own twins, the legs and heads were coming out in the wrong order. “I had to put them all back in and find the front two legs that belonged to the head, and fetch it out,” Rebanks said. A good lamb will come out like a diver. After Rebanks delivered the twins, the mother promptly abandoned one of them. It lay in the grass, bleating, while carrion crows hopped about, hoping to steal its eyes.

Rebanks’s family has worked on the land in Cumbria for six hundred years. His father and grandfather were shepherds, and he dropped out of school at fifteen to help on the farm. But, at twenty-one, sensing that he was missing something, Rebanks took his A-levels at an adult-education center and went to Oxford to study history. For years, he supplemented his income as a shepherd by working as a consultant for UNESCO, studying the impact of tourism on indigenous communities in Africa and Asia, before turning to the dilemmas facing Cumbria’s traditional fell farmers in an era of cheap food, environmental damage, and consumers who have never set foot on a farm. “There is something wrong with our society—which we thought was a good thing—which was this disconnect from the land,” he told me. “It was part of the progress project, wasn’t it? But at no place in that project did anyone think what would happen if no one had any connection with farming or food. There is something flawed in that.”

Photographs by Gregor Schmatz for The New Yorker

It was still before breakfast. We left the barn for the lambing meadow, riding on a red quad bike whose brakes were failing. Rebanks has the active heft of a rugby player, and every so often he jumped off the bike, leaving me to stop it in the mud while he hared off across the grass or over a beck (a small stream) to inspect a ewe or a lamb that he was worried about. He breeds sheep primarily to sell to other farmers for their flocks. A fine Herdwick tup (a male sheep) can sell for five thousand pounds. We reached the pasture where the ewe had become confused over her lambs, and the crows were circling. “It’s a good, old-fashioned muddle-up,” Rebanks said. He scooped up four lambs and nudged the ewes behind them onto a small trailer to sort them out. The new lambs quivered on some yellow plastic sacking next to his blue graphite shepherd’s crook. They were three hours old and ba-a-a-ing at the wrong mothers.

Rebanks began tweeting in January, 2012. For the first two years, he remained anonymous. He had a rule that he would never appear in a picture, or say anything personal. “It would be about the landscape and the sheepdogs and the sheep and the people around me,” he said. But he itched to convey something more substantial about what it means to participate in the land in the twenty-first century, rather than merely visit or admire it. “It’s good to go for a walk,” he said. “It will do you good. But I don’t think you are feeling the same thing as my grandfather did.” He reveres the unknown generations of men and women who crafted Cumbria’s farming ways—“nobodies,” to use Rebanks’s term—but, since he was a teen-ager, he has had a writer’s self-regard. He longed to be heard, and read. “I remember being intrigued or actively jealous of people who had a voice,” he said. “Is that ego? Yes. It’s almost certainly my ego.”