Maharishi Mahesh Yogi (12 January 1918 – 5 February 2008) was born Mahesh Prasad Varma and became known as Maharishi (meaning "great seer") and Yogi as an adult. Maharishi Mahesh Yogi became a disciple and assistant of Swami Brahmananda Saraswati, the Shankaracharya (spiritual leader) of Jyotirmath in the Indian Himalayas. The Maharishi credits Brahmananda Saraswati with inspiring his teachings. In 1955, the Maharishi began to introduce his Transcendental Deep Meditation (later renamed Transcendental Meditation) to India and the world. His first global tour began in 1958. In the late 1960s and early 1970s, the Maharishi achieved fame as the guru to the Beatles, the Beach Boys and other celebrities.  

In 1963, the Maharishi audiotaped the text of the book Science of Being and Art of Living. In the Science of Being, the Maharishi illustrates the concepts of relative existence as the experience of everyday reality through one's senses, and absolute reality as the origin of being, and the source of all creative intelligence. The Maharishi describes this absolute reality, or Being, as unchanging, omnipresent, and eternal. He also identifies it with bliss consciousness. The two aspects of reality, the relative and the absolute, are like an ocean with many waves. The waves represent the relative, and the ocean beneath is the foundation of everything, or Being. Establishing oneself in the field of Being, or unchanging reality, ensures stability. In his Science of Being the Maharishi introduced an additional concept: that of fulfillment viewed as something to be obtained not through exertion or self effort, but through the progressive settling of the mind during the practice of TM.

In his 1967 publication, Bhagavad-Gita: A New Translation and Commentary, the Maharishi describes the Bhagavad Gita as "the Scripture of Yoga". He says that "its purpose is to explain in theory and practice all that is needed to raise the consciousness of man to the highest possible level."

Nancy Cooke de Herrera (born Nancy Veitch, 1922–2013) was an American socialite, fashion expert, and author of three books, including All You Need Is Love: An Eyewitness Account of When Spirituality Spread from the East to the West. She was referred to as one of the pioneers of the spiritual movement in the West.

In 1957, de Herrera won a nationwide contest sponsored by a group of American (USA) magazines. Her prize was a world tour to promote American fashion. Afterwards, the United States Information Service (USIS) enabled her to visit governments around the world and advise them on fashion For twelve years she was a leading figure in the fashion industry and was referred to as the "U.S. Ambassadress of Fashion" while traveling to 15 countries to present American couture.She also presented lectures entitled: "A Travelogue through Fashion" and "Around the World with Nancy Cooke".

Always in search of something more, Nancy Cooke de Herrera has led a life of subtle defiance in order to live a life of great adventure. In this story, Nancy tells the intimate details of her life, which include her friendship with the Maharishi Mahesh Yogi, founding father of Transcendental Meditation, and their time together in the Valley of the Saints with The Beatles, Mia Farrow, Mike Love, Donovan Leitch, and Paul Horn. During her dozens of trips to India and Tibet she has had meetings with the Dalai Lama, the sixteenth Gyalwa Karmapa, Sir Edmund Hillary, the Shah of Iran, King Hussein of Jordan, and Satya Sai Baba. Over the past 50+ years, Nancy has taught Transcendental Meditation to Madonna, Greta Garbo, Rosie O'Donnell, Lenny Kravitz,  Red Hot Chili Peppers, Sheryl Crow, Lena Dunham and many others.

Swami Brahmananda Saraswati (20 December 1868 – 20 May 1953) also known as Guru Dev, was the Shankaracharya of the Jyotir Math monastery in India. Born into a Brahmin family he left home at the age of nine in search of a spiritual master. At age fourteen he became a disciple of Swami Krishnananda Saraswati. At the age of 34 he was initiated into the order of "Sanyas" and became the Shankaracharya of Jyotir Math in 1941 at age 70. His disciples included Swami Shantanand Saraswati, Transcendental Meditation founder Maharishi Mahesh Yogi, Swami Swarupananda Saraswati and Swami Karpatri. Five months before his death in 1953, he made a will naming his disciple, Swami Shantanand Saraswati as his successor.

Mahavatar Babaji is the name given to an Indian saint and yogi by Lahiri Mahasaya and several of his disciples, who reported meeting him between 1861 and 1935. Some of these meetings were described by Pramahansa Yogananda in his book Autobiography of a Yogi, including a first hand report of Yogananda's own meeting with the yogi. Another first hand account was given by Yukteswar Giri  in his book The Holy Science. According to Sri M's autobiography (Apprenticed to a Himalayan Master) Babaji, was Shiva. In the second last chapter of his book, he mentions Babaji changing his form to that of Shiva. All of these accounts, along with additional reported meetings, are described in various biographies. According to Yogananda's autobiography, Babaji has resided for at least hundreds of years in the remote Himalayan regions of India, seen in person by only a small number of disciples and others.

Again, according to his autobiography, shortly before Yogananda left for America in 1920, Babaji came to his home in Calcutta, where the young monk sat deeply praying for divine assurance regarding the mission he was about to undertake. Babaji said to him: "Follow the behest of your guru and go to America. Fear not; you shall be protected. You are the one I have chosen to spread the message of Kriya Yoga in the West."

Sri Yukteswar Giri (10 May 1855 – 9 March 1936) was a Kriya yogi, a Jyotisha (Vedic astrologer), a scholar of the Bhagavad Gita and the Bible, an educator and an astronomer. He was a disciple of Lahiri Mahasaya of Varanasi and a member of the Giri branch of the swami order. Yogananda considered Sri Yukteswar as Jnanavatar, or "Incarnation of Wisdom".

In 1884, Sri Yukteswar met Lahiri Mahasaya, who became his Guru and initiated him into the path of Kriya Yoga. Sri Yukteswar spent a great deal of time in the next several years in the company of his guru, often visiting Lahiri Mahasaya in Benares. In 1894, while attending the Kumbha Mela in Allahabad, he met the Guru of Lahiri Mahasaya, Mahavatar Babaji, who asked Sri Yukteswar to write a book comparing Hindu scriptures and the Christian bible. Mahavatar Babaji also bestowed on Sri Yukteswar the title of 'Swami' at that meeting. Sri Yukteswar completed the requested book in 1894, naming it Kaivalya Darsanam, or The Holy Science.

Paramahansa Yogananda (5 January 1893 – 7 March 1952), was an Indian yogi and guru who introduced millions of westerners to the teachings of meditation and Kriya Yoga through his book, Autobiography of a Yogi.

In 1946, Yogananda published his life story, Autobiography of a Yogi. It has since been translated into 45 languages. In 1999, it was designated one of the "100 Most Important Spiritual Books of the 20th Century".

Autobiography of a Yogi describes Yogananda's spiritual search for enlightenment, in addition to encounters with notable spiritual figures such as Therese Neumann, Anandamayi Ma, Vishuddhananda Paramahansa, Mohandas Gandhi, Nobel laureate in literature Rabindranath Tagore, noted plant scientist Luther Burbank (the book is 'Dedicated to the Memory of Luther Burbank, An American Saint'), famous Indian scientist Sir Jagadish Chandra Bose and Nobel laureate in physics Sir C. V. Raman. One notable chapter of this book is "The Law of Miracles", where he gives scientific explanations for seemingly miraculous feats. He writes: "the word 'impossible' is becoming less prominent in man's vocabulary."

The Autobiography has been an inspiration for many people including Steve Jobs (1955–2011), co-founder, former chairman, and chief executive officer of Apple Inc. In the book Steve Jobs: A Biography the author writes that in preparation for a trip, Mr. Jobs downloaded onto his iPad2, the Autobiography of a Yogi, "the guide to meditation and spirituality that he had first read as a teenager, then re-read in India and had read once a year ever since."

Sathya Sai Baba (born Sathya Narayana Raju; 23 November 1926 – 24 April 2011) was an Indian guru and philanthropist. He claimed to be the reincarnation of Sai Baba of Shirdi.

‍Sai Baba's materialisations of vibhuti (holy ash) and other small objects such as rings, necklaces, and watches, along with reports of miraculous healings, resurrections, clairvoyance, bilocation, and alleged omnipotence and omniscience, were a source of both fame and controversy. His devotees considered them signs of his divinity. The Sathya Sai Organisation, founded by Sai Baba "to enable its members to undertake service activities as a means to spiritual advancement",has over 1,200 Sathya Sai Centres (branches) in 126 countries. Through this organisation, Sai Baba established a network of free hospitals, clinics, drinking water projects, auditoriums, ashrams and schools.

Sai Baba was known for his quote "Love All, Serve All. Help Ever, Hurt Never." Internationally, his devotees gather daily, or weekly on Sundays or Thursdays or both, for devotional prayer, spiritual meditation, service to the community (Seva).  

Followers believed in seeking the spiritual benefit of Sai Baba's darshan scheduled for morning and afternoon each day. Sai Baba would interact with people, accept letters, materialise and distribute vibhuti (sacred ash) or call groups or individuals for interviews. Devotees considered it a great privilege to have an interview and sometimes a single person, group or family was invited for a private interview for answers to spiritual questions and general guidance.

Sivananda Saraswati (or Swami Sivanada) (8 September 1887 – 14 July 1963) was a Hindu spiritual teacher and a proponent of Yoga and Vedanta. Sivananda was born Kuppuswami in Pattamadai, in the Tirunelveli district of Tamil Nadu. He studied medicine and served in British Malaya as a physician for several years before taking up monasticism. He lived most of his life near Muni Ki Reti, Rishikesh.

He was the founder of the Divine Life Society (DLS) in 1936, Yoga-Vedanta Forest Academy (1948) and author of over 200 books on yoga, Vedanta, and a variety of subjects. He established Sivananda Ashram, the headquarters of the DLS, on the bank of the Ganges at Sivanandanagar, 3 kilometres (1.9 mi) from Rishikesh.

‍Sivananda Yoga, the yoga form propagated by his disciple Vishnudevananda, is now spread in many parts of the world through Sivananda Yoga Vedanta Centres. These centres are not affiliated with Sivananda's ashrams, which are run by the Divine Life Society.

Nisargadatta Maharaj (17 April 1897 – 8 September 1981) was an Indian Guru of nondualism, belonging to the Inchagiri Sampradaya, a lineage of teachers from the Navnath Sampradaya and Lingayat Shaivism. The publication in 1973 of "I Am That" talks with Sri Nisargadatta Maharaj, an English translation of his talks in Marathi by Maurice Frydman, brought him worldwide recognition and followers, especially from North America and Europe.

Nisargadatta's teachings are grounded in the Advaita Vedanta interpretation of the Advaita idea Tat Tvam Asi, literally "That Thou Art", (Tat = "Absolute", Tvam = "You", Asi = "are") meaning "You are (actually) Absolute" (who think otherwise). Nisargadatta also had a strong devotion to his own guru, and suggested the path of devotion, Bhakti yoga, to some of his visitors. Nisargadatta deviated from the formal Navnath Sampradaya lineage style of teaching by giving informal discourses for the benefit of Western devotees who did not have access to Dasbodh or other texts, and who were not familiar with Indian traditions and customs. It has been said that Nisargadatta´s style was direct, and even at times aggressive. He very rarely mentioned scriptures or quoted spiritual books. His teachings came from his own experience

Sri Nisargadatta Maharaj gave mantra initiation, with the underlying point being that the mantra was more than sound, it was the Absolute Itself which could be reverberated throughout life in all circumstance.

Rick Rubin (born March 10, 1963) is an American record producer. Along with Russell Simmons, Rubin is the co-founder of Def Jam Records and also established American Recordings and American Songs (Publishing). With the Beastie Boys, LL Cool J, Public Enemy, and Run–D.M.C., Rubin helped popularize hip hop music.

Rubin has also worked with artists such as Red Hot Chili Peppers, Kanye West, Lady Gaga, Slayer, Jay Z, James Blake, Danzig, Dixie Chicks, Tom Petty and the Heartbreakers, Black Sabbath, Slipknot, Metallica, AC/DC, Aerosmith, Weezer, Linkin Park, The Cult, Neil Diamond, The Avett Brothers, Adele, Joe Strummer, Mick Jagger, System of a Down, The Mars Volta, Rage Against the Machine, Audioslave, Sheryl Crow, ZZ Top, Jakob Dylan, Lana Del Rey, Justin Timberlake, Shakira, Ed Sheeran, Damien Rice, Eminem, Frank Ocean, amongst many many others. In 2007, MTV called him "the most important producer of the last 20 years", and the same year Rubin appeared on Time's 100 Most Influential People in the World.