King Bhumibol Adulyadej of Thailand, an American-born monarch whose reign lasted seven decades and captivated a nation, has died. He was 88.

Bhumibol died peacefully on Thursday at 3:52 p.m. at Bangkok’s Siriraj Hospital, the royal palace said in a statement.

Enthroned as a wiry, bespectacled 18-year-old on June 9, 1946, the king became the one enduring force during Thailand’s transition from agrarian backwater to Southeast Asia’s second-biggest economy. His reign encompassed more than two dozen changes of prime minister and 10 coups, the most recent in May 2014.

Listed by Forbes magazine in 2010 as the world’s wealthiest monarch with a $30 billion fortune, a number Thai officials dispute, Bhumibol won the hearts of his people by traveling the nation and meeting with hill tribesmen and the aristocracy alike. He transformed a once-passive monarchy into a political and moral authority that stood above a succession of military-backed governments, though the institution’s role in society was increasingly scrutinized during the political unrest that marred the twilight of his reign.

For a QuickTake explainer on Thailand’s troubled democracy, click here

“Frequent changes of government do not lend themselves to continuity in policy implementation,” wrote Vasit Dejkunjorn, author of “In His Majesty’s Footsteps,” a memoir of 12 years as chief of the royal court police published in 2006. “In this kind of political environment, the much-revered monarchy presented, arguably, the most stable and the best-placed institution.”

Bhumibol had a keen interest in many fields. A composer and saxophonist, he jammed with jazz legends Benny Goodman and Maynard Ferguson, raced sailboats, painted portraits and held patents for water treatment and rainmaking.

Thailand’s 68 million people displayed their reverence for Bhumibol, whose name means “Strength of the Land, Incomparable Power,” by displaying his picture in their homes, businesses and public spaces. Before the color was co-opted by political protesters, millions of citizens from street vendors to corporate executives would wear yellow clothes on Mondays — a day Thais link to that color — to wish him well on the day of the week he was born. His birthday is also Father’s Day.

Royal Power

“To the people in general, the Thai monarchy is not an abstract or irrelevant concept, but a responsive, caring and indispensable institution that is an integral part of their lives,” Anand Panyarachun, a two-time prime minister, said in a speech to the Foreign Correspondents’ Club of Thailand in 2007.

The king seldom spoke to the nation, except for annual televised birthday speeches that sometimes ran for hours. In recent years the speeches stopped and he rarely appeared in public. Under Thailand’s constitutional monarchy, the king is head of state while the prime minister and parliament govern. All legislation requires his seal of approval.

“The president of parliament will come and have a consultation,” Bhumibol said in a 1982 LEADERS magazine interview, “but the king may have more power because the people have faith in their king.”

The king displayed a rare public assertion of his power in May 1992, after government troops killed and wounded dozens of pro-democracy protesters in Bangkok’s streets.

Leaders Prostrate

Bhumibol summoned then-Prime Minister Suchinda Kraprayoon and Chamlong Srimuang, leader of the demonstrations, to the palace. In a televised event, the two were shown lying prostrate before the king as he talked to them.

“There has been an unfathomable loss of public confidence and morale, as well as credibility in the nation’s economy,” he told them, according to a government transcript. “Can there ever be a winner? Of course not.”

The prime minister resigned less than a week later.

In 2006, Thaksin Shinawatra won an election that was boycotted by major opposition parties and resulted in political deadlock. In a speech, Bhumibol called the vote “undemocratic” because there was only “one candidate” and urged the judiciary to “maintain democracy in the country.”

Within weeks a Thai court nullified the balloting. Four months later Thaksin was removed in a coup, and a former army chief and member of the 19-member Privy Council, which advises the sovereign, was named prime minister.

Riots, Arson

Bhumibol moved into a Bangkok hospital in 2009, suffering from various illnesses and back pain, according to the palace. After spending some time at a seaside palace, Klai Kangwon — which means “Far From Worries” — the king was hospitalized again in May 2015.

His youngest daughter, Princess Chulabhorn, made a rare royal appearance on a popular talk show in April 2011 in which she reflected on her father’s health. She said the Thaksin-backed political protests the year before, which ended in riots and arson, had caused the king “great suffering” and pointed to the “torching of our home” as the cause. At least 90 people died in the demonstrations, mostly civilians killed in confrontations with the army.

The king made no public comment in 2014 when Thailand’s army again moved against a democratically-elected government, which had been led by Thaksin’s sister, Yingluck Shinawatra. Coup leader General Prayuth Chan-Ocha said he informed the king of the putsch, and was officially endorsed four days later as the nation’s leader at a ceremony Bhumibol didn’t attend.

Royal Family

The king, who was the world’s longest reigning monarch at the time of his death, is survived by his wife Queen Sirikit, his only son and heir apparent, 64-year-old Crown Prince Maha Vajiralongkorn, and three daughters, the princesses Ubol Ratana, Sirindhorn and Chulabhorn.

Bhumibol was born Dec. 5, 1927, in Cambridge, Massachusetts, where his father, Prince Mahidol, was studying medicine at Harvard University. Before Bhumibol was 2 years old, his father died after moving with the family to Thailand, then known as Siam.

A bloodless coup in 1932 ended absolute monarchy, turning the country’s royals from supreme rulers into figureheads. Bhumibol’s mother, a commoner, had taken him, his older brother Ananda and sister Galyani to live in Lausanne, Switzerland two months before. When King Prajadhipok, their uncle, abdicated in 1935, senior princes passed the mantle to Ananda, then 9.

Brother Shot

In Lausanne, Bhumibol learned French, German and English and developed interests in science, photography and art. He also began playing the piano, clarinet and saxophone.

After spending World War II in Switzerland, the family returned to Thailand in late 1945, and Ananda assumed the throne. Six months later, he was shot in the head and died at age 20 in the palace under circumstances that remain a mystery.

Bhumibol, 18, then became the ninth king of the Chakri Dynasty, which dates back to 1782.

The new monarch returned to Switzerland to resume his studies, switching from science to political science and law at the University of Lausanne.

“I have to leave this capital and leave you because it is essential that I re-create myself,” he said in a radio address before his departure.

‘Crumbling Down’

While in Switzerland, he met Sirikit Kitiyakara, his cousin who was the daughter of a top Thai diplomat in Europe, and they married in Bangkok a week before his coronation on May 5, 1950.

“The palace was crumbling down,” he later told National Geographic magazine about this period. “It was just after the war, and nobody had taken care of things. I had to reconstruct.”

Bhumibol rebuilt the gold-spired Grand Palace, eventually turning it into a magnet for tourism.

Bhumibol’s tours within the kingdom took him to remote villages that had never hosted a monarch, and he pushed for what became 3,000 royal development projects in the country, according to the government.

He visited Europe and the U.S. often in the first 21 years of his reign, encountering such notables as Pope John XXIII, Charles de Gaulle and Elvis Presley.

Ticker-Tape Parade

In 1960, he received a ticker-tape parade in New York, met then-President Dwight D. Eisenhower and addressed a joint session of Congress in Washington. On his final trip to the U.S. in 1967, he was hosted at the White House by Lyndon B. Johnson.

At home, Bhumibol was a staunch U.S. ally during the Vietnam War, when Thailand was an important military staging post. He described antiwar sentiment in the U.S. as “mass brainwashing” and played host to U.S. President Richard Nixon in 1969.

In the last four decades, Bhumibol traveled outside Thailand only once, when in 1994 he presided over the opening of a bridge crossing the Mekong River to neighboring Laos. He sponsored programs aimed at cutting opium production, extended citizenship to hill tribes and brought water and irrigation development to far-off regions.

Lese Majeste

Public discussion of Bhumibol and his political role was curbed under Thailand’s code of lese majeste, laws that can be invoked against anyone accused of defaming, insulting or threatening the king, queen, heir apparent or regent. Offenders face up to 15 years in prison.

Though shielded by these laws, Bhumibol said he didn’t consider himself above criticism. “Because if you say the king cannot be criticized, it means that the king is not human,” he said in his birthday speech in 2005.

Penalties were still imposed, though often reduced. Successive governments resisted calls to amend the legislation from human rights groups, who said the law was too often used as a political tool. After the 2014 coup, junta leader Prayuth vowed there would no longer be mercy for lese-majeste offenders, a stance he had hinted at earlier as army chief.

“If you are living in Thailand and feel uncomfortable with the existence of the monarchy and certain laws, you must find somewhere else to live,” he said in a March 2013 television interview. “Any place where you feel more comfortable.”

Crown Property

The king through the Crown Property Bureau controlled major stakes in some of Thailand’s largest companies, including Siam Cement Pcl, the group founded almost 100 years ago by a royal predecessor, and Siam Commercial Bank Pcl, the nation’s biggest by market value.

Crown Property also managed the monarchy’s real estate holdings, comprising about 16,000 acres that include some of Bangkok’s most expensive land and buildings.

Guarded in his private life, Bhumibol preached a life of moderation befitting his semi-divine status and spiritual role within Buddhism, the religion of more than 90 percent of all Thais. He spent two weeks in a monastery as a monk in 1956, entering with a centuries-old ceremony where he donned saffron-colored robes after his head was shaved.

To read more about the Crown Property Bureau, click here.

In a country where more than half the population works in poor, rural areas, the king said he identified with those who could only afford cheap, unmilled rice.

“Some say it is the poor man’s rice. I too am a poor man,” he said, adding he ate unmilled rice “because it is healthy.”

Whatever the monarchy’s future, “King Bhumibol Adulyadej has sealed his own reputation,” wrote Paul Handley, author of “The King Never Smiles,” a biography published in 2006 and banned in Thailand, according to publisher Yale University Press. “His prestige has survived unscathed, by the virtue of his sheer longevity and his personality — earnest, hardworking, gentle, with an impeccably simple lifestyle.”