Agartha (also spelled Agartta, Agharti, Agarath, Agarta, Agharta, or Agarttha) is a legendary kingdom that is said to be located on the inner surface of the Earth. It is sometimes related to the belief in a hollow Earth and is a popular subject in esotericism, occultism, and the New Age. The concept was introduced by Louis Jacolliot in his 1873 book Les Fils du Dieu, and was expanded upon by authors Alexandre Saint-Yves d'Alveydre, Ferdynand Ossendowski and René Guénon. Saint-Yves's version of the tale would become the most influential.

The belief is in a legendary kingdom that is said to be located on the inner surface of the Earth, sometimes involving a "King of the World". It is sometimes related to the belief in a hollow Earth,and is a popular subject in esotericism and occultism. It is also popular in New Age thought.

Agartha is frequently associated or confused with the Buddhist mythical kingdom Shambhala. In occult thought, they are sometimes conceptualized as being two rival powers, one the "Right Hand Way" and one the "Left Hand Way", with Agartha being conceptualized as the right hand, a land of goodness, in contrast to Shambhala. Where this conceptualization of them as two rival powers comes from is unknown.

Writer and occultist John Michael Greer described Agartha as "one of the most remarkable products of occult history—a rich fabric of legend woven out of a mixture of Victorian anthropology, occult politics, and thin air." Agartha's origins can be traced back to Victorian attempts to interpret mythology through a euhemerist lense, seeing them as containing references to hidden past history; due to influence from the racist theories at the time, this was usually taken from ancient Germanic myths. The Agartha myth was created by French writer Louis Jacolliot, introduced in his book Les Fils du Dieu (1873). Jacolliot was a colonial official in South India, and a writer of many popular books, including a trilogy discussing Indian mythology's relationship to Christianity. In this book, one of the trilogy, he claimed that he had been given access to ancient manuscripts that revealed 15,000 years of Indian history by Brahmin friends of his in Chandernagore, who had told him the story of 'Asgartha'.

Asgartha was said to be an ancient city, the capital of India, that had been destroyed in 5000 BC, shortly before the beginning of the Kali Yuga.He conceptualized the city as ruled by the "Brahmatma", who were the manifestations of God and the chief priests of the Brahmins. His book tells of Agartha's rise and fall. The tale of Agartha has few commonalities with actual Indian mythology, and more similarities to then contemporary theories on prehistory and Norse mythology, and attempts to historicize them. Asgartha, or "Asgarth", is an alternative spelling of Asgard (a location associated with the gods of Norse myth), with an "an" added to make it closer to Sanskrit. Les Fils du Dieu was popular in France, giving a wide exposure to the Agartha concept. Three years after the publication of Jacolliot's book, an anonymous piece of literature called Ghostland, or Researches into the Mysteries of Occultism, was published, discussing Agartha.

In 1886, the French occultist Alexandre Saint-Yves d'Alveydre wrote Mission de l'Inde en Europe, discussing Agartha. Saint-Yves's version of the story would become the most popular and influential. The book discusses how Saint-Yves had allegedly mastered astral travel, and had studied with a man named Haji Sharif (who he claimed was a "high official of the Hindu church", though was actually a parrot shop owner with a Muslim name) who had introduced him to the Agartha idea. In Mission de l'Inde en Europe Saint-Yves said that he had visited Agarttha through astral projection, and gave a detailed description of its marvels. Unlike Jacolliot, Saint-Yves claimed that Agarttha was still in existence underground, having moved there at the beginning of Kali Yuga; he described it as an underground city with millions of inhabitants, under absolute rule from a single figure who had magical powers and advanced technology. The exact influence of Jacillot on Saint-Yves's story is unknown, as it is likely Sharif who introduced him to the concept. The narrative has many commonalities with Jacolliot's original, but with additional concepts taken from the "Mahatma letters" in Theosophy, in addition to the novel The Coming Race (Vril).

In his 1922 book, Beasts, Men and Gods, the Polish explorer Ferdynand Ossendowski relates a story which was imparted to him concerning a subterranean kingdom existing inside the Earth. This kingdom is known to a fictional Buddhist society as Agharti. The idea was expanded upon in René Guénon's works.

In Tibetan Buddhist tradition, Shambhala (Sanskrit: शम्भल, IAST: Śambhala), also spelled Shambala or Shamballa (Tibetan: བདེ་འབྱུང, Wylie: Bde'byung; Chinese: 香巴拉; pinyin: Xiāngbālā), is a spiritual kingdom. Shambhala is mentioned in the Kalachakra Tantra.The Bon scriptures speak of a closely related land called Tagzig Olmo Lung Ring.

The Sanskrit name is taken from the name of a city mentioned in the Hindu Puranas. The mythological relevance of the place originates with a prophecy in Vishnu Purana (4.24) according to which Shambhala will be the birthplace of Kalki, the next incarnation of Vishnu, who will usher in a new age (Satya Yuga); and the prophesied ruling Kingdom of Maitreya, the future Buddha.

Kalachakra tantra Main article: Kalachakra

Manjuśrīkīrti, King of Shambhala Shambhala is ruled by the future Buddha Maitreya. The Shambhala narrative is found in the Kalachakra tantra, a text of the group of the Anuttarayoga Tantras. Kalachakra Buddhism was presumably introduced to Tibet in the 11th century, the epoch of the Tibetan Kalachakra calendar. The oldest known teachers of Kalachakra are Dolpopa Sherab Gyaltsen (d. 1361) and Buton Rinchen Drub (d. 1364).[citation needed]

In the narrative, King Manjuśrīkīrti is said to have been born in 159 BC and ruled over a kingdom of 300,510 followers of the Mlechha religion, some of whom worshiped the Sun. He is said to have expelled 20,000 people from his domain who clung to Surya Samadhi (solar worship) rather than convert to Kalachakra (Wheel of Time) Buddhism. After realizing these were the wisest and best of his people and how much he was in need of them, he later asked them to return and some did. Those who did not return are said to have set up the city of Shambhala. Manjuśrīkīrti initiated the preaching of the Kalachakra teachings in order to try to convert those who returned and were still under his rule. In 59 BC he abdicated his throne to his son, Puṇḍārika, and died soon afterward, entering the Sambhogakaya of Buddhahood.

Portrait of an Alti Himalian Shaman. Detail from "A Sorceress from Tungusy" 1812–1813 by: E. Karnejeff The Kalachakra tantra prophesies that when the world declines into war and greed, and all is lost, the 25th Kalki king Maitreya will emerge from Shambhala, with a huge army to vanquish Dark Forces and usher in a worldwide Golden Age. This final battle is prophesied for the year 2424 or 2425 (in the 3304th year after the death of the Buddha). Thereafter, Buddhism would survive another 1,800 years.

Western reception Tibet and Tibetan Buddhism were largely unknown in the West prior to the beginning of the 20th century. The name itself, however, was reported as early as the 17th century, by way of Estêvão Cacella, the Portuguese missionary who had heard about Shambhala (transcribed as Xembala), and thought it was another name for Cathay or China. Cacella in 1627 headed to Tashilhunpo, the seat of the Panchen Lama and, discovering his mistake, returned to India.

Neo-Theosophy Later esoteric writers further emphasized and elaborated on the concept of a hidden land inhabited by a hidden mystic brotherhood whose members labor for the good of humanity. Alice A. Bailey claims Shamballa (her spelling) is an extra-dimensional or spiritual reality on the astral plane, a spiritual centre where the governing deity of Earth, Sanat Kumara, dwells as the highest Avatar of the Planetary Logos of Earth, and is said to be an expression of the Will of God.[better source needed]

Expeditions and location hypotheses Nicholas and Helena Roerich led a 1924–1928 expedition aimed at Shambhala. They also believed that Belukha Mountain in the Altai Mountains was an entrance to Shambhala, a common belief in that region. They led a second expedition to look for Shambhala in Mongolia between 1934 and 1935.

Inspired by Theosophical lore and several visiting Mongol lamas, Gleb Bokii, the chief Bolshevik cryptographer and one of the bosses of the Soviet secret police, along with his writer friend Alexander Barchenko, embarked on a quest for Shambhala, in an attempt to merge Kalachakra-tantra and ideas of Communism in the 1920s. Among other things, in a secret laboratory affiliated with the secret police, Bokii and Barchenko experimented with Buddhist spiritual techniques to try to find a key for engineering perfect communist human beings. They contemplated a special expedition to Inner Asia to retrieve the wisdom of Shambhala – the project fell through as a result of intrigues within the Soviet intelligence service, as well as rival efforts of the Soviet Foreign Commissariat that sent its own expedition to Tibet in 1924.

French Buddhist Alexandra David-Néel associated Shambhala with Balkh in present-day Afghanistan, also offering the Persian Sham-i-Bala, "elevated candle" as an etymology of its name. In a similar vein, the Gurdjieffian J. G. Bennett published speculation that Shambalha was Shams-i-Balkh, a Bactrian sun temple.

Hitler sent several expeditions to Tibet in the 1930s "to contact the Agartha and Shambala", supposedly part of Nazi esotericism.