Every morning for 20 years, Karl-Heinz Martens steered his yellow mail truck through the narrow streets of Eutin, a market town arranged around a little castle in northern Germany, near the Baltic Sea. On his route, Martens would drive through miles of farms and fields before disappearing into a deep, enchanted forest, where he unlocked a gate using a special key and reversed into his parking spot—as all mailmen do—facing outward to ensure a quick exit. As he crunched into the woods carrying his mailbag, his tidy beard and glasses were sometimes flecked with snowflakes or sleet, and every morning, just before the clock struck 12, he arrived beneath a towering oak.

“People used to memorize my route and wait for me to arrive because they couldn’t believe that a postman would deliver letters to a tree,” Martens told the press, who called the now-retired mailman the “messenger of love.” The Bräutigamseiche, or Bridegroom’s Oak, is the only tree in Europe with its own mailing address. Every day the 500-year-old tree receives dozens of lonely-hearts letters, and singletons arrive from near and far to reach into a small knothole in the trunk, hoping to find a match. The tree is believed to possess magical matchmaking powers.

According to legend, the tree and its longest-serving mailman are together responsible for more than a hundred marriages. Despite holding the most romantic job in Europe, Martens was a middle-aged divorcé who did not believe in fate. The scores of relationships he helped create, he said when we spoke last year, were “just lucky coincidences.” But that was before the magical oak changed his life, too, and created a happy ending to rival any fairy tale.

In 1984, when Martens first took up the role, the Berlin Wall still separated West Germany (where the Bridegroom’s Oak grew) from the country’s Communist East. The mailman’s personal life had split down the middle too, when his marriage fizzled out and he found himself alone, with shared custody of his 12-year-old son. “I was fed up with women back then,” he said, and had sworn off dating. Sometimes Martens found his love-letter duties tiresome. People assumed the Bridegroom’s Oak was his only stop, he complained, but the tree was part of a challenging delivery route controlled by Deutsche Bundespost, the mail service that employed him. By noon the tourists would be waiting, he half-joked, to “steal my time.”

The magical tree drew tourists and fans of German folklore, in which forests are overrun with lonely princesses, magical spells, and romance (Disneyland’s castle is based on a Bavarian palace). Martens, who speaks in Low German, the blue-collar dialect of the country’s lowlands, was ordered by his superiors to educate the tourists. His ancient tongue added a certain authenticity to a story that sounds like other tales from the German forests, such as “Snow White” and “Little Red Riding Hood.”

“Once upon a time, there was a son of a prince,” Martens began. “He was left in this forest and no one cared about him until a very beautiful girl rescued him. And because he was so grateful to her, he planted a tree.” That seedling, he said, grew into a mighty, 82-foot-tall oak.

“That’s the short version,” Martens told me as we trudged through the forest late last year, kicking up leaves.

The story of how the tree became known for matchmaking is a little longer, he explained. In 1890, a chocolate maker from nearby Leipzig fell in love with the forester’s daughter, but her father forbade the relationship. Instead, the two lovers left each other notes in the knothole of the oak tree. Eventually, the girl’s father had a change of heart. He threw a wedding ceremony where his daughter’s love had bloomed. There, in the shadow of the branches, the bride and groom kissed, and the tree found its name. It was after that, Martens said, that other love letters started to arrive.

By 1927 the Bridegroom’s Oak was overwhelmed with mail. The post office made the unusual decision to give the tree its own mailing address. Deutsche Bundespost even erected a 10-foot-tall ladder up to the mailbox, to help people reach in to open, read, and respond to love letters at senders’ provided return addresses. The only rule, Martens told me sternly, is that if you open a letter and don’t respond, you must place it back in the tree for someone else to find. He added that young women believe that if they walk around the tree three times under a full moon while thinking of their beloved, they “will be married within the year.”

Over the years, scores of sweethearts who were united by the tree have carved their initials into its branches, and the tree wears these scars as evidence of its powers. This litany of happy couples includes an American girl and the English army officer she met by writing to the oak. They moved to Scotland to be together, according to newspapers. Also engraved in the trunk are the initials of a young lady who was too shy to write to the tree, but found love after her friends wrote on her behalf. She married a German soldier.

Courtesy of Karl-Heinz Martens

When Martens was running late or found himself in no mood to tell a fairy tale, he photocopied the legend and handed it out. But as the tree’s popularity increased, the mailman soon found himself talking to radio and television reporters, whose stories would prompt even more people to write. “I usually came here with a handful of letters, about five each day,” he told me. “When the press was here and did a story on the tree, then you would have about 50 letters a day.” He remembers just a few days when the oak received no letters, he said. “I can count on two hands the days I haven’t been here, except for weekends and holidays.”

Though public speaking was difficult at first, with daily practice Martens started to relish sharing the story of the tree. “I have always regarded this task as a great honor,” Martens said. “I was picked for the job because I had a talent for chattering. I have a French mother,” he added, by way of explanation. And so begins a story of an unbelievable coincidence, and the first time Martens’s life was turned upside down by a letter out of the blue.

Martens’s mother, Yvette, was a teenager during the Second World War. She spent her days hanging around her parents’ laundromat in France, where they cleaned and starched the uniforms of the German army. One day, she caught the eye of a sergeant major. “Three beautiful young girls were running around and he picked the youngest and said, ‘That’s the one,’” Martens said. “And that’s my mother.” She was just 17 when he was born, Martens told me, and she named him after his parachutist father. By the end of the war, Karl-Heinz Sr. was missing, presumed dead.

Miraculously, his father resurfaced some months later in a military hospital in Italy. He was transferred to his hometown, Flensburg, where he recovered from his injuries. Yvette brought Martens to Germany as an infant to reunite him with his father, but she was so homesick that she yearned to return to France. Martens’s grandparents insisted that the baby remain in Germany. He had a cold and was too sick to make the journey by train, they said. Yvette, just a child herself, agreed, and left Martens to be raised by his father. Growing up with a stepmother, he only found out about his real mother in France when he was 12 or 13, and had no way of finding her.

“My stepmother used to work at the telecommunications office and my father worked at the post office,” Martens recalled. In 1961 he followed his father into the mail industry, taking a job at the post office, where he sorted mail and returned lost letters to their sender. One day, when Martens was about 25, a letter came across his desk addressed to him at his grandparents’ old house. They had long since moved out, and when he saw the sender’s name, Martens said he was “baff”—the German word for dumbstruck. He rushed the letter to his boss. “This letter,” he said, “is from my mother.” He needed to open it, he begged, knowing that to do so was a mortal sin for a postal worker. “Alright,” his supervisor said, “you can open the letter with me as a witness.”

With shaking hands, Martens read the note. His real mother was alive and well. The French army was searching for him as a deserter, she wrote, and urged him to meet her in France. It was a lot to take in. When Martens told his father, he turned cold. “Well, you know what you have here,” his father warned. “You don’t know what it will be like down there.” But Martens fired up his Volkswagen Beetle. I asked how he felt as he drove to the French border. It was summer, he said, and the Beetle’s engine is in the back, so the cabin felt like a sauna. No, I asked, how did you feel about the meeting?

Excuse me,” he said. “What would you feel like if you were meeting your mother for the first time?”

When he met his mother at the border, she was with her husband and her brother. During the few days they spent together, Martens said he felt like they had never parted. His mother’s husband was a French cook and his meals were “top-class,” Martens said. It all started to make sense: He had always enjoyed French food and culture, and soon he identified in his nature a quirky sense of humor that was entirely French. Slowly, Martens and his mother rebuilt their relationship. He visited her up to five times a year, or whenever he could take time off work. And he never forgot that it was all thanks to a lucky letter.   

During the 1960s, Deutsche Bundespost underwent a major modernization. A new program for the sorting of letters reduced the service’s number of letter centers from 3,600 to just 350, and in 1967 Martens was relocated from his job in Kappeln to another in Kiel. Then, in 1972, when his son, Olaf, was born, he moved to his girlfriend’s birthplace, Eutin. They married, but their relationship began to crumble, he said. Their divorce was straightforward and drama-free. After they signed the papers they enjoyed a meal with their son, as if to say, We will always be your parents. Martens took custody of Maica, the family’s jet-black mutt, whom they’d lovingly named after a brand of sausage. When I asked whether Maica ever joined Martens on his rounds, the former mailman was appalled. That would be verboten, he said.

Martens was 38 when he started delivering mail to the Bridegroom’s Oak. The delivery route was not desirable. Previous mailmen, mostly bachelors, complained about the mile-long detour. Ernst Pries, who was the messenger of love in the 1950s and ’60s, told The Boston Globe: “I wasn’t very thrilled at first about having to go out of my way to deposit what I thought were stupid letters.”

Martens had no time for affairs of the heart either. He grew up in Flensburg, the no-nonsense town near Denmark where his father was born, home to the German Department of Motor Vehicles and its point system for punishing unruly motorists. Martens always felt destined for a job in the public sector, and believed that delivering love letters was his civic duty. You could set your watch by Martens’s arrival at the Bridegroom’s Oak.

Germany’s present-day mail service is a testament to the country’s efficiency. The service is famously fast, and 94 percent of letters reach their recipient the next working day. By the time Martens started delivering letters to the Bridegroom’s Oak in 1984, he was one of 543,200 Deutsche Bundespost employees; the West German post office had more manpower than the national army and was just as regimented. One dedicated mailman in Munich once discovered a quicker route between postal depots, but was hauled before a judge and faced criminal charges for not following protocol.

Deutsche Post, the mail service on the other side of the Berlin Wall, was quite the opposite. The East German secret service, the Stasi, regularly ransacked packages for cash and valuables, while economic problems made for a sketchy service starved of raw materials. Still, letters from people in East Germany hoping to make contact with the West found their way to the Bridegroom’s Oak. “I wanted to write back,” Martens said, “but my boss recommended me not to.”

“I can’t answer every question. If they were asking what cars were driven here, I can’t write back, ‘BMW.’” He said women asked about nylon tights. “I didn’t have any idea about that. Who am I?” Martens scoffed. “I would just send them a pre-written letter back,” he said curtly. The photocopied page he sent comprised a biography of the tree and some interesting facts.

In 1988, Martens delivered a letter to the tree bearing the postmark of Bad Salzungen, one of East Germany’s oldest saltwater spa towns. The letter was mailed by a lonely 19-year-old nurse named Claudia. She spent her evenings alone, clandestinely tuned in to West German television stations, looking for entertainment. When she saw a news item about the Bridegroom’s Oak, her heart filled with excitement. “At the end, the address of the tree faded in,” she told me. Claudia picked up her pen and scribbled down: “Dodau 99 Dodau Forsthaus, 23701 Eutin, Germany.”

Shortly after Martens delivered her letter, it was discovered by a 36-year-old farmer’s son. Friedrich Christiansen was an agricultural-machine technician who lived in Malente in West Germany, just a short drive from the forest. Tired of striking out with local girls at farmers’ dances, he was intrigued when his mother spoke of the tree of love. One day he wandered into the forest and peered into the knothole. When he read Claudia’s hopeful letter, he thought she sounded like a perfect match. “I liked her handwriting,” he told me.

Their letters grew in passion and promise, but politics prevented Friedrich and Claudia from forging a relationship from opposite sides of the border. Like the chocolatier’s son and the forester’s daughter who first discovered the Bridegroom’s Oak, they exchanged love letters and prayed that their circumstances might change. One day, after much frustration, the farmer purchased a map to find out where Claudia lived—he had to see her in the flesh. Information was scant about the other side, and some German maps were printed with large blank sections. He nervously headed for the border.

At the checkpoint, he lied to the guards. He told them he was visiting a cousin. But he was secretly headed to a rendezvous about 100 miles northeast of Frankfurt, where he and Claudia finally embraced. “She had a moped!” Friedrich said. Despite having only one brief meeting, by the summer of 1989 they were engaged.

Left: Martens visits the tree today (Jeff Maysh); Right: A younger Martens poses for an undated photo at the oak during his rounds (Courtesy of Karl-Heinz Martens)

Witnessing romances like this one blossom started to thaw Martens’s cold heart. He tried to date, he admitted, but the dating pool in a town of 20,000 was so small that it made romance awkward. No one ever seemed to be “the one,” he told me. His life revolved around delivering the mail on time, taking Maica on long walks, and social events at the local sports club. Martens was proudly self-reliant and didn’t need a wife. Visitors to his spotless apartment couldn’t believe a woman didn’t live there, he said.

Like Martens, Karin Grüttemeier did not believe in fate. Karin lived in Hörstel near the Dutch border and had heard about the Bridegroom’s Oak years ago, but never thought she’d write to it. Then one Christmas her husband died. For the first time in years, she felt so alone. “I wasn’t feeling very well back then,” Karin told me. She tried to enjoy her summer holidays in the Bavarian Forest, and while she was there she was reminded of the matchmaking tree. Could the Bridegroom’s Oak help her find love again? “I’m gonna send a letter there,” she decided one day in the late 1980s.

Around that time, Hans Peter Gerörde was visiting Germany’s Baltic coast to tell his aunt some difficult news. His marriage was over, and a divorce loomed. When the aunt suggested he visit the Bridegroom’s Oak, Hans Peter also thought the magical tree was worth a try. One afternoon, after Martens had delivered the morning’s letters, Hans Peter pulled from the knothole the note from Karin, the widower from Hörstel. He wrote a reply the same day. Just weeks later, they were in each other’s arms. The tree had struck again. It was, Karin said, “love at first sight.”

Martens heard that phrase a lot over the years. He told me about another gentleman who arrived in Eutin for treatment at a health resort. When the weather turned too cold to enjoy the Baltic coastline, he took a trip inland instead. He found himself at the Bridegroom’s Oak, with his hand in the knothole. The letter he found, Martens said, was from a woman who lived just a few miles from his home, hundreds of miles away in Ruhr, near Dortmund. Naturally, they met, fell in love, and married, Martens said.

Martens was never invited to the weddings, but that didn’t bother him. He watched the oak’s leaves turn brown, then green, and brown again. His dark beard became gray. Tensions between East and West Germany thawed. And the footsteps of the lonely young women who traced a path around the tree wore away at the forest floor, already compressed from decades of tourist traffic. To preserve the tree, foresters erected a fence around it, and only Martens’s mail truck was allowed to drive up to the ladder. Letter seekers had to arrive on foot.

Then one day, as Martens climbed the wooden steps for maybe the thousandth time, he reached into his mailbag and noticed an unusual letter.

It was addressed to him.

The sender was Renate Heinz, a wine merchant in her late 50s. Renate was divorced, with an adult son from her marriage to a policeman. She was career-focused and liked to spend her free time in front of the television. It was there that she saw a news item on the Bridegroom’s Oak, and an interview with the mailman, Karl-Heinz Martens. “I sat in front of the TV and immediately felt a connection with him,” she told me. Renate recalled that when Martens announced he was single, she turned to her son and said: “I’ll change that!”

Though she had never done anything like it, Renate felt the urge to scribble a note on the back of her business card and mail it off to the Bridegroom’s Oak. When Martens read it, he was captivated by the straight-talking message, which simply read: “I want to get to know you!” When he noticed that the sender was from Saarbrücken, which he knew to be near the French border, it all started to make sense.

That fits, Martens thought: She was practically French. “That’s the reason I got in touch,” he said. “I called her. I’m too lazy to write.” Soon they were talking on the telephone for hours at a time.

“I had quite the phone bill,” he said.

“One day he sent me a photo of his dog,” Renate said. When she saw Maica staring out of the photograph, she was smitten. Before long, she and Martens were talking about a meeting.

“I didn’t know Saarbrücken, but France was close,” Martens said. He was due to visit his mother, and he thought he could visit Renate on the way. The meeting was, he told himself, “nonbinding.” If I don’t like her, he thought, I’ll just get back in the car.

When Martens told a friend at the sports club about his blind date, she was surprised. “Well, you have to know what you’re doing,” she said. Martens wasn’t nervous. He explained that in telling the legend of the tree to strangers every day, he’d gained a unique confidence. And anyway, he had done this before. A strange letter had arrived out of the blue, and he’d driven to France to meet a woman, not knowing what to expect. So one Saturday morning, he opened his car door and let Maica hop in. Then he sat behind the wheel and started the engine.

Saarbrücken is a large baroque town split in half by the Saar river and sutured together by a dozen brick and stone bridges. When Martens arrived that afternoon, he worried about how he would find Renate. “I didn’t know the city,” he said. “So she had to guide me somewhere; we didn’t have smartphones back then.” Renate had given him directions to a parking lot, and there he saw a woman standing alone. She wore a summer dress and had short, dark-blond hair. It had to be her. She was so friendly and charming that any awkwardness melted away.

“We liked each other!” Martens recalled. “Maica of course also had a great connection” with Renate, he added. And Renate later admitted to a newspaper: “I fell in love with Maica straight away too.” The date went so well that Martens spent “a couple of days” in her apartment, he told me. “The first date lasted two days?” I asked. “We had been calling each other for weeks before that. We weren’t strangers anymore,” Martens explained. But that wasn’t the end of it. He still had to see his mother. And he didn’t want to leave Renate.

Martens and Renate embrace after marrying in 1990 (Courtesy of Karl-Heinz Martens)

“I had to warn my mother that I wasn’t coming alone,” Martens said. Soon, Renate and Maica were in the car, and they were speeding out of Saarbrücken to meet his mother in France. On their first date.

At the time, other unexpected developments rocked Germany. In 1989, following the surprise downfall of the German Democratic Republic, the Berlin Wall tumbled and Germany reunified. Friedrich and Claudia, the couple who had exchanged letters for nearly two years across the border, were now able to marry, and tied the knot in May of 1990. Around then, after a short romance, Renate agreed to move in with Martens in Eutin. This didn’t seem crazy, she said. “If you got to know each other via the Bridegroom’s Oak, it’s different than with someone you meet in a disco.”

Renate and Martens shared a love for fine dining. Renate worked as a verkosterin—a taster—and she sold fine wine, especially reds. In the evenings, Renate would bring home a special bottle from work and treat Martens to a robust red from Argentina or South Africa. He liked everything about her, he told me. They called each other schatz—“sweetheart.”  

One day, they were drinking beer at his favorite restaurant, Tönnchen, when out of the blue Martens said: “Actually, we could get married.” He said it so casually, as if the idea had just come to him. Renate was thrilled. They ordered another round of beer to celebrate.

In 1994, they exchanged rings in Eutin’s town hall. “We didn’t marry in a church; we aren’t religious,” Martens said. He decided to marry her after five years, he said, because she was “the one.” After the ceremony they were “ordered” to the tree by friends who had prepared a surprise buffet under the branches. Later, they partied at Tönnchen, where postal workers packed the dance floor.

The local newspaper called it the hochzeit des jahres—the “wedding of the year.”

“I still come here often,” Martens told me as we circled the tree together last year. About 12 years ago, arborists diagnosed the oak with a fungal infection, and they had to chop off a number of its limbs to prevent the infection from spreading. Around this  time, Martens was diagnosed with leukemia. Foresters noticed that the tree was growing more slowly than before. “It was totally damaged,” Martens told me. “If you look up you might see ropes up there in the tree. Because they’re afraid the tree will break apart. They thought about cutting it down.”

“But right now I have other problems, of course,” he said. Old age and his illness have made travel difficult. He hasn’t visited Renate’s son, who lives in America, for some time. “He is one of the 10 best hairdressers in the U.S.,” Martens said. “He lives in the Hamptons in New York. I haven’t been there because my wife would never set a foot on a plane.” He said he likes to stay close to Renate.

“We’ve been married for 24 years,” he said.

When we reached the tree, he pulled out a letter and read a note from a woman called Petra: “Hello dear stranger, If you like to laugh, enjoy the quiet moments of life … then you should definitely contact me.” Martens paused before reading the last sentence, which seemed to hang in the air: “When you’re alone, everything is half as much fun.”

Martens put it back.

As we stood looking up at the giant tree, he told me that his wife had lung cancer and was very unwell. “The chemo doesn’t work anymore,” he said quietly. Then, some months after we met, Martens wrote with some sad news. His wife passed away, he said. Renate’s funeral was held on Valentine’s Day.

I thought about how in the forest that afternoon, Martens had explained how the Bridegroom’s Oak had changed his opinion on “lucky coincidences.” “I do believe there’s something magical about the tree,” Martens had conceded, as a brown leaf fell from the oak and landed perfectly on his shoulder. “I’m getting goose bumps just thinking about it,” he’d said. This had happened to other messengers of love too. Pries, the reluctant mailman in the 1960s, once said: “After I saw how many compatible people the tree bought together, I started to enjoy my job.”

There are no plans to cut down the Bridegroom’s Oak, and you can write to it today if you’re lonely and bored with Tinder. Internet dating can’t compete with the Bridegroom’s Oak, Martens said. He won’t join up. He told me about one of Germany’s most popular online-dating sites, which demands its members complete a long questionnaire before matching partners based on a complicated points system. “On the internet, questions match people,” he said, “but at the tree, it’s a beautiful coincidence, like fate.”