As the wife of a U.S. diplomat, Penelope Laingen had trekked to Pakistan, Afghanistan and Malta, loyally serving alongside her husband in the long tradition of Foreign Service families.

“From boiling vats of water to dropping calling cards,” she once remarked, “from packing and unpacking our households to attending endless receptions, from parasites and culture shock to performing charitable acts,” the duties thrust upon Mrs. Laingen had accustomed her to a life of hardship — but also, she said, one of “purpose and meaning.”

Her most public ordeal began on Nov. 4, 1979, when Iranian militants stormed the U.S. Embassy in Tehran, where her husband, L. Bruce Laingen, was chargé ­d’affaires. Laingen — one of three hostages detained, separately from their embassy colleagues, at the Iranian Foreign Ministry — was the highest-ranking official among the 52 Americans held in captivity for 444 days.

That event, known as the Iran hostage crisis, led to the deaths of eight U.S. servicemen in an aborted rescue attempt and contributed to the defeat of President Jimmy Carter in the 1980 election. For Mrs. Laingen, as for other relatives of the hostages back in the United States, it was a personal trauma — a time of fear and worry, of missed birthdays and lonely holidays, and a period in their lives when, as Mrs. Laingen put it, “you couldn’t think about anything else.”

Just as her husband served as de facto leader of the hostages, relaying messages to Washington until his communications were severed, Mrs. Laingen became a champion of their families at home. She helped found the Family Liaison Action Group (FLAG), acted as a go-between with the State Department and offered support during the emotional and bureaucratic challenges that arose during their loved ones’ absence.

To the American public, she was perhaps best known for the yellow ribbon she tied around the oak tree outside her home in Bethesda, Md., a symbol of devotion to the hostages that she displayed until her husband returned. The yellow ribbon soon proliferated across the United States and has endured in American culture as a sign of solidarity with deployed troops, among other causes.

Mrs. Laingen died April 3 in Marshall, Va., at the home of one of her three sons. She was 89 and had breast cancer, said her son Chip Laingen. Bruce Laingen, a former U.S. ambassador to Malta, died in 2019 at 96.

Many accounts trace the inspiration for the yellow sash to the hit song “Tie a Yellow Ribbon ’Round the Ole Oak Tree.” Written by Irwin Levine and L. Russell Brown, it was recorded by Tony Orlando and Dawn in 1973 and covered by artists including Perry Como, Frank Sinatra and Dolly Parton.

Mrs. Laingen told the Miami Herald that she was “no big fan” of Tony Orlando’s nightclub act. But there was a hopeful message in his song, which tells the story of a newly released prisoner who makes his way home aboard a bus, looking for the yellow ribbon that he had asked his beloved to display if she would take him back.

Mainly, Mrs. Laingen said, she wished to offer Americans a “constructive” way of channeling their concern for the hostages. Thousands of Americans took to bedecking their trees in yellow ribbons; among them were the Carters, who invited Mrs. Laingen to tie one around the National Christmas Tree at the White House.

Behind the scenes, Mrs. Laingen acted as a tireless advocate for her husband, the other Americans in captivity and their families.

“She was just all over the place at the department making sure that the concerns of these real live human beings who were in this limbo through no fault of their own — that their needs were being addressed,” said Marianne Benson, whose father, consular officer Robert Anders, was one of six hostages sheltered at the Canadian Embassy, as dramatized in the 2012 Hollywood movie “Argo.” “She just kept insisting in her own diplomatic but forceful way that the needs of the families absolutely could not be overlooked.”

Mrs. Laingen recalled feeling particular pressure as the wife of the chargé ­d’affaires to act in a way befitting her husband’s rank and her attendant role. She did not have the freedom, she said, to weep on television or unload her frustration with the State Department, which by her account gave her “not one iota of support” during the hostage crisis.

“I formed the Iranian hostage family group, put out a monthly bulletin, started the yellow ribbon campaign — and to this day I have not heard one word of verbal thanks from any State Department official for the role I played,” Mrs. Laingen told the New York Times in 1984. “I stood up in many of those meetings with the families and said, ‘Look, we cannot go against our Government.’ I have given my whole life to this service and have come up with nothing.”

But she found profound kinship with the families of the other hostages, describing their bond as “a fraternity that will be lifelong.”

The hostages were released on Jan. 20, 1981, the day President Ronald Reagan took office. A Washington Post reporter, writing about their return to the United States, described a “profusion of yellow ribbons blooming like an early spring on everything from trees and telephone poles to pet poodles.”

When Bruce Laingen arrived at his house in Bethesda, amid a celebration that included a performance by a local marching band, he personally took down the yellow ribbon from his oak tree. He was home, and there were two years of Christmas presents waiting for him.

Penelope Lippitt Babcock — known as Penne — was born in Ann Arbor, Mich., on Dec. 1, 1931. Early in her childhood, she moved to the Washington area, where her father worked for the Federal Housing Administration. Her mother was a homemaker.

Mrs. Laingen was a 1949 graduate of Bethesda-Chevy Chase High School and received a bachelor’s degree in English from George Washington University in 1953. She was working for the FBI as a researcher when she met her future husband on a blind date. They were married in 1957.

Early in her husband’s Foreign Service career, Mrs. Laingen accompanied him on a posting to Karachi, where she arrived with a 2-year-old son, gave birth to a second son and suffered a miscarriage.

One day, she recalled in a 1986 interview with the Association for Diplomatic Studies and Training, “my two-year-old had five-inch worms coming out of his little bottom, which made me weak in the knees, my baby had a staph infection, which he had picked up in the hospital, great big sores all over him at three weeks old.”

Mrs. Laingen, too, was ill. With no electricity, she managed to pull together a dinner for Letitia “Tish” Baldrige, first lady Jacqueline Kennedy’s social secretary, who unexpectedly joined the family that evening for dinner. Mrs. Laingen later helped arrange a visit by the first lady herself.

After her husband’s return from captivity, Mrs. Laingen hung a yellow ribbon on her oak tree on only one other occasion — in the early 1990s, when two of her sons were serving in the Navy in the Persian Gulf War.

Survivors include her three children, Bill Laingen of O’Fallon, Mo., Chip Laingen of Woodbury, Minn., and Jim Laingen of Marshall, all retired Navy officers; a brother; 10 grandchildren; seven great-grandchildren; and two great-great-grandchildren.

In 1991, Mrs. Laingen donated the original sash honoring her husband to the Library of Congress. “Just as the Stars and Stripes had its Betsy Ross,” Librarian of Congress James H. Billington remarked at the time, “so the yellow ribbon has its Penne Laingen.”

In 2013, the Laingens sold their Bethesda home, which was torn down and another house built in its place. To their gratitude, the oak tree, to which Mrs. Laingen said they had “an almost mystical attachment,” was left untouched. It was adorned with a small, decorative and permanent yellow ribbon.