He wrapped the Reichstag in Berlin in silvery fabric, dressed several islands near Miami in flamingo-pink skirts, ran a 24-mile-long fence through Northern California and installed 7,500 goal-post-like gates in New York’s Central Park. His installations, which in some cases attracted millions of visitors, expanded the definition of contemporary art.

Christo, 84, a Bulgarian-born environmental artist known for his monumental works, died May 31 at his home in New York City. His office announced the death in a statement but did not give a precise cause.

Bespectacled and nerdy in appearance, Christo was the Evel Knievel of artists, pulling off seemingly impossible feats, such as erecting thousands of giant umbrellas simultaneously in the United States and Japan and persuading hundreds of German lawmakers to let him wrap the Reichstag. Measured by the number of people who saw his work, he was probably the most successful artist of the late 20th and early 21st centuries.

New Yorker art critic Calvin Tomkins marveled at Christo’s “grandiose, ephemeral, absurdly beautiful spectacles,” while noting that their very accessibility evoked “disdain and hostility . . . in certain quarters.” Among art-world insiders, Christo’s installations, which required armies of workers and millions of dollars to pull off, were sometimes viewed as a triumph of spectacle over art.

But his thousands of drawings and models — which he sold to finance his projects — were art by anybody’s definition. From 1987 to 2003, Tomkins reported, Christo had sold more than $66 million worth of his work.

For most of his career, Christo collaborated with his wife, the former Jeanne-Claude Denat de Guillebon; together, they completed 23 large public projects. They developed ideas jointly, after which Christo made drawings and scale models while Jeanne-Claude (she, too, was known by her first name) handled logistics. Although the body of work was initially attributed to Christo, in 1994, they retroactively applied the joint name “Christo and Jeanne-Claude” to all their large-scale pieces.

Christo rarely talked about the meaning of his work, but he traced its roots to his years in art school in Sofia, Bulgaria. The Communist government wanted to impress passengers aboard the Orient Express, traveling between Paris and Istanbul, and dispatched students to the countryside to cultivate an ordered look.

Christo, as he explained to Surface magazine in 2018, had to tell residents “that they should keep everything very clean and organized. I was talking to farmers and workers, ordinary people not involved with art.”

He added: “All that is part of what I am doing today. I’m still talking to people who have not the slightest idea what art is, who are not interested in art. I enjoy that adventure.”

Christo Vladimirov Javacheff was born in the Bulgarian city of Gabrovo on June 13, 1935 (the same day as his wife). His father ran a fabric factory, and his mother was the secretary at the Academy of Fine Arts in Sofia. In 1957, he stowed away on a train that took him across the Iron Curtain to Vienna.

He soon moved to Paris, where he supported himself by painting portraits. He met Jeanne-Claude, the Moroccan-born daughter of a French army officer, in 1958, when he was commissioned to paint a portrait of her mother.

While pregnant with Christo’s child in 1959, she married a man her parents considered more suitable. But she left her husband after three weeks, later telling The Washington Post, “His key didn’t fit my lock.” She gave birth to a son, Cyril, in 1960 and married Christo two years later.

In 1961, Christo and Jeanne-Claude produced their first joint work, a temporary installation on the docks in Cologne, Germany, consisting of oil drums covered in tarps. The next year, they used more oil drums to close off a narrow street in Paris, creating a kind of “iron curtain” in protest of the Berlin Wall. The couple moved to New York in 1964.

Five years later, they were invited by an Australian collector to wrap nearly two miles of coast and cliffs along Little Bay, outside Sydney. The project required almost 1 million square feet of fabric and 17,000 person-hours to erect. It was dismantled after 10 weeks, setting a precedent: All of the couple’s large-scale works were temporary.

Their first monumental installation in the United States — a 200-foot-long curtain across a canyon in Colorado — was put in place on Aug. 10, 1972. Bright orange and strung across a giant gulch, it looked like a fabric dam or the broken smile of a geologically scaled jack-o’-lantern.

But the “Valley Curtain” lasted only 28 hours before it was destroyed by gale-force winds. The project was the subject of an Oscar-nominated documentary by filmmakers David and Albert Maysles, as were several other Christo and Jeanne-Claude installations.

In 1972, they turned their attentions to “Running Fence,” a fabric strip nearly 18 feet high and 25 miles long meant to cross Sonoma and Marin counties in Northern California. Nine lawyers were engaged to win approval from 59 landowners. Construction, using 2 million square feet of nylon hung from 2,000 steel posts, was completed in 1976; the fence remained up for two weeks.

The couple later surrounded 11 islands in Miami’s Biscayne Bay with millions of square feet of pink polypropylene fabric and in 1985 wrapped the Pont Neuf, the oldest stone bridge in Paris, in sand-colored cloth. Their next installation involved setting up thousands of umbrellas simultaneously in Ibaraki, Japan, and at the Tejon Ranch in Southern California, in the fall of 1991.

The $26 million project seemed like an innocent expression of international solidarity. But high winds knocked over an umbrella in California, killing one person and injuring several others. Christo and Jeanne-Claude immediately ordered the umbrellas closed “out of respect.” A second death — of a worker — occurred when the umbrellas were being taken down.

Meanwhile, the couple had spent more than two decades seeking approval to wrap the Reichstag, the seat of Germany’s Bundestag (parliament). In June 1995, the building was covered in more than 1 million square feet of fireproof polypropylene fabric, which gave it an otherworldly appearance and, to many, symbolized Germany’s rejection of its past.

New York Times architecture critic Paul Goldberger wrote that the Reichstag, “a heavy, bombastic building that epitomizes German excesses of the late 19th century, is rendered light, almost delicate.” The project, he observed, “got Berlin into more of a celebratory mood than anything since the fall of the wall.”

Their efforts to install 7,503 metal frames festooned with orange fabric in Central Park began in 1979. A breakthrough came 22 years later with the election of Mike Bloomberg, an arts patron, as mayor. With Bloomberg’s support, the installation, known as “the Gates,” was unveiled on Feb. 12, 2005. About 5 million people visited “The Gates” during its 16-day run; 600 “gatekeepers” distributed a million free fabric samples as souvenirs. The project’s cost — $21 million — was borne entirely by Christo and Jeanne-Claude.

After Jeanne-Claude’s death in 2009, Christo continued executing projects they had planned together, notably working to create a silvery canopy over 42 miles of the Arkansas River in central Colorado. The project, mostly on federal land, faced opposition from a local group and was canceled by Christo in January 2017, after the election of Donald Trump.

“I use my own money and my own work and my own plans because I like to be totally free,” Christo told the Times. “And here now, the federal government is our landlord. They own the land. I can’t do a project that benefits this landlord.” He calculated that he and Jeanne-Claude had completed 23 projects but had failed to realize more than twice that many.

In 1962, he had the idea to wrap the Arc de Triomphe in Paris. Delayed by the coronavirus pandemic, the project, involving 25,000 square meters of silvery blue fabric and 7,000 meters of red rope, is now slated to open in September 2021 — almost 60 years after Christo conceived it.

Christo lived and worked in a loft building in New York’s SoHo neighborhood that he and Jeanne-Claude bought in 1973, the year he became an American citizen. Survivors include his son, filmmaker and photographer Cyril Christo of Santa Fe, N.M.; two brothers; and a grandson.

Of his large pieces, Christo told the Times in 2014: “They’re totally irrational and absolutely unnecessary. They cannot be bought, you can’t charge for tickets. The world can exist without them. And this carries a kind of absolute freedom.”