He was born at Bangkok. When he was only eleven years old, he was sent to study at the Royal Military Academy Sandhurst. Later he studied history and law at Christ Church, Oxford. He was greatly influenced by English culture.
When his brother Crown Prince Vajirunhis unexpectedly died at age 16, Vajiravudh was named crown prince. After his father's death, he became the sixth monarch of the Chakri Dynasty.
His reigning title was Phra Mongkut Klao Chaoyuhua. He was second son of King Chulalongkorn.
Following the death of his elder half-brother, Crown Prince Maha Vajirunhis, in 1895, he was appointed Crown Prince. He was educated in England and his great love of literature and poetry in both Thai and English together with his scholastic abilities was later to manifest itseft during his reign.
Among his lasting achievements were devising a system of transliteration of Thai into English and of translating the entire works of Shakespeare into Thai.
His passion for traditional Thai theater and ballet has left a mass of published scores which form the basis of the study of these arts to the present day.
King Vajiravudh's coronation in Bangkok on December 2, 1911 was an occasion of much splendor. Among those present at the ceremonies were members of the royal families of Great Britain, Denmark, Sweden, Russia and Japan (the largest gathering of European royalty on the Asian Continent either before or since).
The Russian imperial jewelers, Messrs. Carl Fabergé, set up a temporary shop within the hallowed portals of the Oriental Hotel to coincide with the festivities. In 1916 King Vajiravudh declared war on Germany and Thai troops fought with the Allies during the latter part of World War I.
Although rumors surround the sexual preferences of King Rama VI, currently little is known about the lives of people with alternative genders and sexualities in Bangkok prior to the mid-twentieth century.
One area of debate concerns the applicability of Western terms such as "gay" or "bisexual" in the Thai context. Through most of his reign there was a good deal of criticism of the king. Some argued that the real power in the state lay with the king's favourites, the young men of his inner entourage for whom he had written plays and with whom he played games and organised clubs and societies.
It was commonly known, but never spoken of, that the King was in fact an "erratic homosexual".
He died in Bangkok at the early age of 44. Without a direct male heir, King Vajiravudh's brother Prajadhipok became the new monarch.