Once dismissed as hippie mysticism, the Hindu practice of mind control known as transcendental meditation gradually gained medical respectability.
He began teaching TM in 1955 and brought the technique to the United States in 1959. But the movement really took off after the Beatles attended one of his lectures in 1967 and visited his ashram in India in 1968, bringing along such famous friends as Donovan.
Once there, the Maharishi had a falling out with the rock stars after rumors emerged that he was making inappropriate advances on attendee Mia Farrow. John Lennon was so angry he wrote a bitter satire, "Sexy Sadie," in which he vowed that the Maharishi would "get yours yet."
The Maharishi insisted he had done nothing wrong and years later McCartney agreed with him. Deepak Chopra, a disciple of the Maharishi's and a friend of George Harrison's, has disputed the Farrow story, saying instead that the Maharishi had become unhappy with the Beatles because they were using drugs.
The Maharishi retreated last month into silence at his home on the grounds of a former Franciscan monastery close to the German border, saying he wanted to dedicate his remaining days to studying the ancient Indian texts that underpin his movement.
"He had been saying he had done what he set out to do," Roth said late Tuesday.
With the help of celebrity endorsements, Maharishi - a Hindi-language title for Great Seer - parlayed his interpretations of ancient scripture into a multi-million-dollar global empire. His roster of famous meditators ran from Mike Love of the Beach Boys to Clint Eastwood and Chopra, a new age preacher.
After 50 years of teaching, Maharishi turned to larger themes, with grand designs to harness the power of group meditation to create world peace and to mobilize his devotees to banish poverty from the earth.
Director David Lynch, creator of dark and violent films, lectured at college campuses about the "ocean of tranquility" he found in more than 30 years of practicing transcendental meditation.
In a telephone interview with The Associated Press, Lynch said it has aided him "in every aspect of life," including his creative work.
He said he believed the Maharishi has laid the groundwork for world peace, even if that was not immediately apparent from world affairs.
"The world appears in bad shape on the surface, but I compare it to a tree: there are yellow sickly leaves dropping off but the Maharishi has brought nourishment to the roots. Hang on for a little while longer, it's coming."
Lynch said he experienced a mixture of feelings about the Maharishi's death: "It's a big, big sorrow, and yet you know, he's in a very good place. He always was. Peace is coming."
Some 5 million people devoted 20 minutes every morning and evening reciting a simple sound, or mantra, and delving into their consciousness.
"Don't fight darkness. Bring the light, and darkness will disappear," Maharishi said in a 2006 interview, repeating one of his own mantras.
Donations and the $2,500 fee to learn TM financed the construction of Peace Palaces, or meditation centers, in dozens of cities around the world. It paid for hundreds of new schools in India.
In 1971, Maharishi founded a university in Fairfield, Iowa, that taught meditation alongside the arts and sciences to 700 students and served organic vegetarian food in its cafeterias.
Supporters pointed to hundreds of scientific studies showing that meditation reduces stress, lowers blood pressure, improves concentration and raises results for students and businessmen.
Skeptics ridiculed his plan to raise $10 trillion to end poverty by sponsoring organic farming in the world's poorest countries. They scoffed at his notion that meditation groups, acting like psychic shock troops, can end conflict.
"To resolve problems through negotiation is a very childish approach," he said.
In 1986, two groups founded by his organization were sued in the U.S. by former disciples who accused it of fraud, negligence and intentionally inflicting emotional damage. A jury, however, refused to award punitive damages.
Over the years, Maharishi also was accused of fraud by former pupils who claim he failed to teach them to fly. "Yogic flying," showcased as the ultimate level of transcendence, was never witnessed as anything more than TM followers sitting in the cross-legged lotus position and bouncing across spongy mats.
Maharishi was born Mahesh Srivastava in central India, reportedly on Jan. 12, 1917 - though he refused to confirm the date or discuss his early life.
He studied physics at Allahabad University before becoming secretary to a well known Hindu holy man. After the death of his teacher, Maharishi went into a nomadic two-year retreat of silence in the Himalayan foothills of northern India.
With his background in physics, he brought his message to the West in a language that mixed the occult and science that became the buzz of college campuses. He described TM as "the unified field of all the laws of nature."
Maharishi's trademark flowing beard and long, graying hair appeared on the cover of the leading news magazines of the day.
But aides say Maharishi became disillusioned that TM had become identified with the counterculture, and he spent more time at his ashram in Rishikesh in the Himalayan foothills to run his global affairs.
In 1990 he moved onto the wooded grounds of of the monastery in Vlodrop, about 125 miles southeast of Amsterdam.
Concerned about his fragile health, he secluded himself in two rooms of the wooden pavilion he built on the compound, speaking only by video to aides around the world and even to his closest advisers in the same building.
John Hagelin, a theoretical physicist who ran for the U.S. presidency three times on the Maharishi-backed Natural Law Party, said that from the Dutch location Maharishi had daylong access to followers in India, Europe and the Americas.
"He runs several shifts of us into the ground," said Hagelin, Maharishi's closest aid, speaking in Vlodrop about his then-89-year-old mentor. "He is a fountainhead of innovation and new ideas - far too many than you can ever follow up."