(CNN) -- The Rev. Sun Myung Moon -- a controversial religious and political figure who founded the Unification Church, a major institution in East Asia and beyond that gained fame decades ago for its mass weddings -- died early Monday in South Korea, the church said.
The Universal Peace Federation said on its website that Moon died early Monday morning of complications related to pneumonia. He was 92.
"Our True Father passed into the spiritual world at 1:54 AM Monday, September 3rd, Korea time," a message on a Unification Church English-language website said.
His funeral will be held on September 15 after nearly two weeks of mourning, the church said in a statement. Moon's mortuary will be open for visitors to pay respects from Thursday until the funeral, it said.
"Rev. Moon died from overwork, from frequent trips aboard, including to the U.S., and from morning prayers which caused respiratory disease," Ahn Ho-yeol, a church spokesman said.
He will be buried on Mount Cheonseong in the northern South Korean province of Gyeonggi. In its statement, the church described the mountain as the "holy land" of the church.
The Washington Times, one of several publications that Moon founded, similarly reported Moon's death.
"Words cannot convey my heart at this time," Thomas P. McDevitt, the Times' president, said in a story on the newspaper's website. "Rev. Sun Myung Moon has long loved America, and he believed in the need for a powerful free press to convey accurate information and moral values to people in a free world."
McDevitt added that the Times is a "tangible expression of those two loves." In 2010, the newspaper was sold to a group operating on Moon's behalf, according to a statement on the paper's website.
Doctors put Moon in intensive care in a Seoul hospital last month after he fell ill, said Ahn, the church spokesman, at the time. Physicians then gave him a 50% chance of survival.
Days later, one of his sons, the Rev. Hyung Jin Moon, noted in a sermon posted on a church website that his father had multiple health problems in recent years, including heart surgery performed in the United States about 10 years ago. But still, he pushed on with his life's mission.
"Father, who is responsible to save the world, pushed himself way beyond his limits," said the son, who himself has a leading role in the church.
Moon had been a high-profile international evangelist for decades, having said that Jesus Christ came to him in the 1930s and "told him to finish (Jesus') mission," according to James Beverley, a professor at the Tyndale University College and Seminary in Toronto.
The Unification Church believes Jesus was divine but that he is not God, a stance that puts it outside the bounds of traditional Christianity. Followers regard Moon as the messiah.
His church officially started in the 1950s, with missionaries being dispatched around the world by the end of that decade. His was one of several religious movements that emerged after World War II and the Korean War in South Korea and Japan, drawing from "a tremendous pool of people ... looking for answers as to why the world had turned (against them)," said Virginia Commonwealth University professor David Bromley.
Globally, the church's reach may have peaked in the 1970s and early 1980s, as hundreds of thousands joined the singular religious movement, said Beverley. Critics have said the controversial Moon leads a cult whose followers were colloquially known as "Moonies."
"Rev. Moon demanded a lot of members -- a lot of (them) left their families and they lived very sacrificially, especially in the 1970s," said Beverley. "Moon claims to be the true father of humanity, (and) his wife is the true mother."
Today, the professor estimates that the Unification Church has hundreds of thousands of followers still in South Korea and Japan, with far fewer elsewhere around the globe.
In his role as church leader, Moon is famous for conducting mass weddings, including one in 1982 at New York City's Madison Square Garden and one in 1995 in South Korea uniting 360,000 couples.
"It was his way of emphasizing the importance of the family, plus all these couples get married under his blessing and that is basically their path to heaven," said Beverley.
Arranged matches are a common practice for members of the Unification Church. Howard Self, a spokesman for organizers of a 1997 mass ceremony at Washington's Robert F. Kennedy Stadium, said after that event that those blessed by Moon could then be legally married later "in their own countries."
"Even before you're matched, you know that you're going to base your relationship on internal aspects because you don't know what the person's going to look like," said a man before his 1997 union to a woman he had met less than a week earlier.
Moon has had influence in other ways as well. He grew a massive, diverse business empire -- including holdings in industries such as chemicals, arms manufacturing, mining and pharmaceuticals -- at the same as his church grew, providing him with wealth "that allowed him to ... pursue his religious agenda," said Bromley.
Even after his church's membership in the United States dwindled in recent years, Moon stayed relevant by appearing frequently and sponsoring events for journalists, politicians, scientists and others at which he sometimes offered high-profile individuals large amounts of money to appear, noted Bromley.
He also helped create news publications, universities, religious institutions and other groups. Some such organizations Moon founded stress interfaith dialogue and peace, like the Universal Peace Federation, which advocates "building a world of peace in which everyone can live in freedom, harmony, cooperation and prosperity."
He's also run into trouble with the law, serving a federal prison term in the United States for tax evasion. From 2003 to 2005, the British government prohibited him from traveling to that country, according to a U.S. State Department report.
Still, Moon continued to be regarded highly elsewhere -- including in Washington.
A video from 2004, posted on the website of what was then known as the Interreligious and International Federation for World Peace, showed a ceremony taking place in a U.S. Senate office building attended by Moon and several members of Congress. Speaking Korean, Moon declares himself the messiah and says he'd spoken to the spirits of Nazi leader Adolf Hitler and Soviet leader Joseph Stalin, both of whom he said found strength in his teachings and mended their ways.
Rep. Danny Davis, D-Illinois, is seen reading a poem and wearing white gloves and carrying a crown on a pillow to Moon and his wife. Davis said later he thought it was all part of an interfaith peace ceremony, adding that Moon didn't ask his "permission to call himself the messiah."
Moon was traditionally a strong supporter of Republican politicians, including Richard Nixon and Ronald Reagan, said Eileen Barker, a professor at the London School of Economics and Political Science.
He was also known for being "virulently anti-communist," having been imprisoned in North Korea during the Korean War before being freed by the allies, she said.
Moon softened his hard line on North Korea, though, over time -- even meeting North Korea's founder (and grandfather of its current leader), the late Kim Il Sung, and investing money in the north. He also took pride in talking with Mikhail Gorbachev before the Soviet Union's collapse, calling such meetings a part of the unification movement that connects with the "messiah" and therefore was part of "the restoration," according to Bromley.
In the sermon from August 19 posted online, the Rev. Hyung Jin Moon talked about his father's illness and praised his efforts over the years, as well as stating some of the family's political positions as regards China, Russia and others.
The younger Moon also made a point to thank those who have been praying for his father's health.
"We need to remember, father is not just a normal person," said the Rev. Hyung Jin Moon. "Father's body is not just a normal body."
CNN's Richard Greene, K.J. Kwon and Greg Botelho contributed to this report.